Revert "Adds url to gclient json"

This reverts commit 2f2b0593e0.

Sample breakage:

http://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20ChromeOS/builds/67372/steps/gclient%20sync/logs/stdio

BUG=
R=grt@chromium.org, hinoka@chromium.org

Review URL: https://codereview.chromium.org/267393007

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@268887 0039d316-1c4b-4281-b951-d872f2087c98

gclient.py

@@ -1746,7 +1746,6 @@ def CMDsync(parser, args):
       slns[normed] = {
           'revision': d.got_revision,
           'scm': d.used_scm.name if d.used_scm else None,
-          'url': d.url if d.url else None,
       }
     with open(options.output_json, 'wb') as f:
       json.dump({'solutions': slns}, f)