IRC commit-bot: Replace ViewVC link with SVN number

This patch is in response to a post on blink-dev suggestion that the
ViewVC link posted by commit-bot in #blink is too long and should be shortened.
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/82jGnz_uvRI

NOTRY=TRUE
BUG=336709

Review URL: https://codereview.chromium.org/143823011

git-svn-id: svn://svn.chromium.org/blink/trunk@165511 bbb929c8-8fbe-4397-9dbb-9b2b20218538