Tag two enumeration constants with @since.

* subversion/bindings/javahl/src/org/apache/subversion/javahl/ConflictDescriptor.java
  (ConflictDescriptor.Reason.addad, ConflictDescriptor.Reason.replaced):
   Add version tags to docstrings.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1451811 13f79535-47bb-0310-9956-ffa450edef68