codereview.py: fix for compatibility with hg >=1.4.3
codereview.py: fix for compatibility with hg >=1.4.3

hg.parseurl now returns a two-value tuple; codereview.py expected 3.
Changed to merely take the first return value.

R=rsc, iant
CC=golang-dev
http://codereview.appspot.com/223087

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go