Revert part of b0a0ea7 (bug 1144417) since th-client isn't using requ…

…ests

Since the switch to requests has been backed out (437a3c3), we also need
to undo the service-side change that was made separately to support it.

treeherder/etl/th_publisher.py

@@ -30,11 +30,11 @@ def post_treeherder_collections(th_collections):
                 th_request.get_uri(th_collections[project].endpoint_base)))
         response = th_request.post(th_collections[project])
 
-        if not response or response.status_code != 200:
+        if not response or response.status != 200:
             errors.append({
                 "project": project,
                 "url": th_collections[project].endpoint_base,
-                "message": response.content
+                "message": response.read()
             })
     if errors:
         raise CollectionNotLoadedException(errors)