Fix failed searches of just parentheses

If the query were just parentheses, like ")(",
l2cs.convert would return an empty string, causing
the subsequent search to fail. This moves the empty
query check later in the code to avoid that issue.

fixes reddit/reddit#618

r2/r2/lib/cloudsearch.py

@@ -825,9 +825,6 @@ class CloudSearchQuery(object):
         self.results = None
 
     def run(self, after=None, reverse=False, num=1000, _update=False):
-        if not self.query:
-            return Results([], 0, {})
-
         results = self._run(_update=_update)
 
         docs, hits, facets = results.docs, results.hits, results._facets
@@ -907,6 +904,8 @@ class CloudSearchQuery(object):
                    u'rank': u'-text_relevance'}
         
         '''
+        if not query and not bq:
+            return Results([], 0, {})
         response = basic_query(query=query, bq=bq, size=num, start=start,
                                rank=sort, search_api=cls.search_api,
                                faceting=faceting, record_stats=True)