   Fixed Issue #2220: propdel returns success on deleting a non-existent prop.

   * subversion/libsvn_wc/props.c
     (svn_wc_prop_set2): Modified with check to see
     if property already exists.

   * subversion/tests/clients/cmdline/prop_tests.py
     (remove_nonexistent_prop): Added function
     to test removal of non-existent property.


