Revision 1885600

Follow up to r1884427, r1885557: mailer.py: Fix mixture of bytes/str.

* tools/hook-scripts/mailer/mailer.py
  (): Rename imported function urllib.parse.quote from urlib_parse_quote to
   _url_quote.
  (remove_leading_slashes): Treat path as a bytes, if it is not None.
  (Commit.__init__): Fix the case that SVN_PROP_REVISION_LOG property is NULL.
  (DiffURLSelections._get_url): Use renamed urllib.parse.quote function and
   'if' expression for readability.
  (generate_content): Set data.log as s str.
  (TextCommitRenderer.render): Treat data.log as a str.