googleplus: fix positional argument warning from google-api-client

specifically:

execute() takes at most 1 positional argument (2 given) (/base/data/home/apps/s~brid-gy/7.402950590977246624/local/lib/python2.7/site-packages/oauth2client/_helpers.py:132)

from googleapiclient.http.HttpRequest.execute()

granary/googleplus.py

@@ -120,15 +120,15 @@ def request_with_etag(*args, **kwargs):
     try:
       if activity_id:
         call = self.auth_entity.api().activities().get(activityId=activity_id)
-        activities = [call.execute(http)]
+        activities = [call.execute(http=http)]
       elif search_query:
         call = self.auth_entity.api().activities().search(
           query=search_query, maxResults=min(count, SEARCH_MAX_RESULTS))
-        activities = call.execute(http).get('items', [])
+        activities = call.execute(http=http).get('items', [])
       else:
         call = self.auth_entity.api().activities().list(
           userId=user_id, collection='public', maxResults=count)
-        resp = call.execute(http)
+        resp = call.execute(http=http)
         activities = resp.get('items', [])
         etag = resp.get('etag')
     except HttpError, e:
@@ -180,7 +180,7 @@ def set_comments(req_id, resp, exc, activity=None):
                             'resharers', 'share')
 
     if batch._requests:
-      batch.execute(http)
+      batch.execute(http=http)
 
     for a in activities:
       self.postprocess_activity(a)
@@ -203,7 +203,7 @@ def get_comment(self, comment_id, activity_id=None, activity_author_id=None,
     """
     # https://developers.google.com/+/api/latest/comments
     call = self.auth_entity.api().comments().get(commentId=comment_id)
-    cmt = call.execute(self.auth_entity.http())
+    cmt = call.execute(http=self.auth_entity.http())
     return self.postprocess_comment(cmt)
 
   def postprocess_activity(self, activity):