Improve error message as suggested by Greg here:  http://svn.haxx.se/dev/archive-2011-05/0625.shtml
Improve error message as suggested by Greg here: 
http://svn.haxx.se/dev/archive-2011-05/0625.shtml

* subversion/libsvn_client/copy.c
  (repos_to_repos_copy): reword error message


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1124380 13f79535-47bb-0310-9956-ffa450edef68

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