IRC commit-bot: Make svn revision appear in the beginning of bot message.

It is easier to read the svn version quickly if it appears in the beginning of the message.

R=alancutter, dstockwell

Review URL: https://codereview.chromium.org/145103003

git-svn-id: svn://svn.chromium.org/blink/trunk@166120 bbb929c8-8fbe-4397-9dbb-9b2b20218538