ra_serf: Match error message returned by ra_dav when a property change fails.
ra_serf: Match error message returned by ra_dav when a property change fails.

This makes ra_serf's error text pass lock test #1 (lock a file and verify that
it's locked).

* subversion/libsvn_ra_serf/commit.c
  (proppatch_resource): Wrap error with the magic error string from ra_dav.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@859419 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion