Working on isue #4326 (update javahl with new 1.8 APIs).

* subversion/bindings/javahl/native/SVNClient.cpp (SVNClient::commit):
   Call svn_client_commit6 (with externals drilldown enabled) instead
   of svn_client_commit5.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1455645 13f79535-47bb-0310-9956-ffa450edef68