gerrit_util: work with all paths.

BUG=chromium:664664
TEST=local
  - Didn't work locally, now it does.

Change-Id: I5d470feda420342b0fb00a56e42a2b7d00257920
Reviewed-on: https://chromium-review.googlesource.com/411284
Reviewed-by: Aaron Gable <agable@chromium.org>
diff --git a/gerrit_util.py b/gerrit_util.py
index a433e83..0c73785 100755
--- a/gerrit_util.py
+++ b/gerrit_util.py
@@ -266,10 +266,11 @@
   else:
     LOGGER.debug('No authorization found for %s.' % bare_host)
 
-  if 'Authorization' in headers and not path.startswith('/a/'):
-    url = '/a%s' % path
-  else:
-    url = '%s' % path
+  url = path
+  if not url.startswith('/'):
+    url = '/' + url
+  if 'Authorization' in headers and not url.startswith('/a/'):
+    url = '/a%s' % url
 
   if body:
     body = json.JSONEncoder().encode(body)