Fix a typo in an error message.
Fix a typo in an error message.

* subversion/include/svn_error_codes.h
  (SVN_ERR_RA_DAV_PROPPATCH_FAILED): Fix typo in error message.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion