Merge pull request steve-community#50 from gregorschatz/master

fix steve-community#49  OCPP ChangeConfiguration with custom key is broken

Author: goekay

src/main/java/de/rwth/idsg/steve/ocpp/task/ChangeConfigurationTask.java

@@ -25,21 +25,21 @@ public OcppCallback<String> defaultCallback() {
     @Override
     public ocpp.cp._2010._08.ChangeConfigurationRequest getOcpp12Request() {
         return new ocpp.cp._2010._08.ChangeConfigurationRequest()
-                .withKey(params.getConfKey())
+                .withKey(params.getKey())
                 .withValue(params.getValue());
     }
 
     @Override
     public ocpp.cp._2012._06.ChangeConfigurationRequest getOcpp15Request() {
         return new ocpp.cp._2012._06.ChangeConfigurationRequest()
-                .withKey(params.getConfKey())
+                .withKey(params.getKey())
                 .withValue(params.getValue());
     }
 
     @Override
     public ocpp.cp._2015._10.ChangeConfigurationRequest getOcpp16Request() {
         return new ocpp.cp._2015._10.ChangeConfigurationRequest()
-                .withKey(params.getConfKey())
+                .withKey(params.getKey())
                 .withValue(params.getValue());
     }