AMBARI-1297. Edit User: if "old password" is not specified and "new password" is specified, password update silently fails. (Jaimin Jetly via yusaku)

git-svn-id: https://svn.apache.org/repos/asf/incubator/ambari/trunk@1440244 13f79535-47bb-0310-9956-ffa450edef68