For the Ev2 FS commit editor: ignore NULL properties when altering a directory.
For the Ev2 FS commit editor: ignore NULL properties when altering a directory.

* subversion/libsvn_fs/editor.c
  (alter_directory_cb): Only alter props if given.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1425234 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion