moved the call to remove group membership inside of the null check

[shsteimer]

This is to fix an NPE I found in the logs with a ensureGroup config with operation of remove. The second (or any subequent time) the remove is activated, the NPE is thrown.

com.adobe.acs.commons.users.impl.EnsureAuthorizableException: Failed to ensure [ REMOVE ] of Group [ my-group ]
	at com.adobe.acs.commons.users.impl.EnsureGroup.ensure(EnsureGroup.java:152)
	at com.adobe.acs.commons.users.impl.EnsureGroup.activate(EnsureGroup.java:348)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.felix.scr.impl.inject.BaseMethod.invokeMethod(BaseMethod.java:224)
	at org.apache.felix.scr.impl.inject.BaseMethod.access$500(BaseMethod.java:39)
	at org.apache.felix.scr.impl.inject.BaseMethod$Resolved.invoke(BaseMethod.java:617)
	at org.apache.felix.scr.impl.inject.BaseMethod.invoke(BaseMethod.java:501)
	at org.apache.felix.scr.impl.inject.ActivateMethod.invoke(ActivateMethod.java:302)
	at org.apache.felix.scr.impl.inject.ActivateMethod.invoke(ActivateMethod.java:294)
	at org.apache.felix.scr.impl.manager.SingleComponentManager.createImplementationObject(SingleComponentManager.java:298)
	at org.apache.felix.scr.impl.manager.SingleComponentManager.createComponent(SingleComponentManager.java:109)
	at org.apache.felix.scr.impl.manager.SingleComponentManager.getService(SingleComponentManager.java:906)
	at org.apache.felix.scr.impl.manager.SingleComponentManager.getServiceInternal(SingleComponentManager.java:879)
	at org.apache.felix.scr.impl.manager.AbstractComponentManager.activateInternal(AbstractComponentManager.java:749)
	at org.apache.felix.scr.impl.manager.AbstractComponentManager.enableInternal(AbstractComponentManager.java:675)
	at org.apache.felix.scr.impl.manager.AbstractComponentManager.enable(AbstractComponentManager.java:430)
	at org.apache.felix.scr.impl.manager.ConfigurableComponentHolder.enableComponents(ConfigurableComponentHolder.java:657)
	at org.apache.felix.scr.impl.BundleComponentActivator.initialEnable(BundleComponentActivator.java:341)
	at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:390)
	at org.apache.felix.scr.impl.Activator.access$200(Activator.java:54)
	at org.apache.felix.scr.impl.Activator$ScrExtension.start(Activator.java:265)
	at org.apache.felix.utils.extender.AbstractExtender.createExtension(AbstractExtender.java:259)
	at org.apache.felix.utils.extender.AbstractExtender.modifiedBundle(AbstractExtender.java:232)
	at org.osgi.util.tracker.BundleTracker$Tracked.customizerModified(BundleTracker.java:482)
	at org.osgi.util.tracker.BundleTracker$Tracked.customizerModified(BundleTracker.java:415)
	at org.osgi.util.tracker.AbstractTracked.track(AbstractTracked.java:232)
	at org.osgi.util.tracker.BundleTracker$Tracked.bundleChanged(BundleTracker.java:444)
	at org.apache.felix.framework.util.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:916)
	at org.apache.felix.framework.util.EventDispatcher.fireEventImmediately(EventDispatcher.java:835)
	at org.apache.felix.framework.util.EventDispatcher.fireBundleEvent(EventDispatcher.java:517)
	at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:4542)
	at org.apache.felix.framework.Felix.startBundle(Felix.java:2173)
	at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1372)
	at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:308)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException: null
	at com.adobe.acs.commons.users.impl.EnsureGroup.ensureRemoveMembership(EnsureGroup.java:326)
	at com.adobe.acs.commons.users.impl.EnsureGroup.ensureRemoval(EnsureGroup.java:197)
	at com.adobe.acs.commons.users.impl.EnsureGroup.ensure(EnsureGroup.java:136)
	... 37 common frames omitted

[update-changelog]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would update the CHANGELOG.md file with this pull request.

[coveralls]

Pull Request Test Coverage Report for Build 4377

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage remained the same at 52.495%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
bundle/src/main/java/com/adobe/acs/commons/users/impl/EnsureGroup.java	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
bundle/src/main/java/com/adobe/acs/commons/users/impl/EnsureGroup.java	2	0.0%

Totals
Change from base Build 4373:	0.0%
Covered Lines:	13234
Relevant Lines:	25210

---

💛 - Coveralls

[davidjgonzalez]

Can you update the change log as well? Otherwise looks good

Changelog was updated