Minor Usability tweak for post-commit hook

Review Request #759 — Created March 11, 2009 and submitted — Latest diff uploaded

Review Board SVN (deprecated)
This is a trivial change for the post-commit hook that lets it still work if the URL in the commit message lacks a trailing slash.  I came across this when some of my users would put something like this in the commit message:

Review: http://REVIEWBOARD_URL/r/123

instead of

Review: http://REVIEWBOARD_URL/r/123/
This change has been in use on my install for a while and is working as expected.