[FAB-11191] Fix invalid security link in docs

RTD page
http://hyperledger-fabric.readthedocs.io/en/latest/CONTRIBUTING.html#reporting-bugs
has an invalid link to:
https://wiki.hyperledger.org/security/bug-handling-process
it should be:
https://wiki.hyperledger.org/security

The following line should trigger  an auto-transition in
Jira to Done upon merge of the CR:
FAB-11191 #done

Change-Id: Ic56546c9566d23f98674f2a2c599085e74b01058
Signed-off-by: David Enyeart <enyeart@us.ibm.com>

Author: denyeart

docs/source/CONTRIBUTING.rst

@@ -67,7 +67,7 @@ reported, then you might add a comment that you also are interested in seeing
 the defect fixed.
 
 .. note:: If the defect is security-related, please follow the Hyperledger
-          `security bug reporting process <https://wiki.hyperledger.org/security/bug-handling-process>`.
+          `security bug reporting process <https://wiki.hyperledger.org/security>`__.
 
 If it has not been previously reported, create a new JIRA. Please try to provide
 sufficient information for someone else to reproduce the