Fix mailer.py problem with show_nonmatching_paths set to yes and a configuration that sends commit messages to multiple places.
Fix mailer.py problem with show_nonmatching_paths set to yes and a
configuration that sends commit messages to multiple places.

Patch by: Robert Spier <rspier@pobox.com>

* tools/hook-scripts/mailer/mailer.py
  (DiffGenerator.__init__): Initialize self.diff and self.diff_url to None.

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