Applied bug fix from trunk r1639867.
Applied patch from jira issue - OFBIZ-4362 - MapKey for CMS content cannot be updated.
Thanks Manuela for reporting the bug, Thanks Deepak for providing the patch for this issue.

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/branches/release13.07@1639868 13f79535-47bb-0310-9956-ffa450edef68