Fix "local variable 'url' referenced before assignment" error.

TBR=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6792050

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@80452 0039d316-1c4b-4281-b951-d872f2087c98

scm.py

@@ -217,6 +217,7 @@ class GIT(object):
     # The -100 is an arbitrary limit so we don't search forever.
     cmd = ['git', 'log', '-100', '--pretty=medium']
     proc = gclient_utils.Popen(cmd, stdout=subprocess.PIPE)
+    url = None
     for line in proc.stdout:
       match = git_svn_re.match(line)
       if match: