Race condition in GridFS test.

test_gridfs_secondary_lazy asserts that get_last_version on a secondary raises
NoFile. This fails if setUp()'s dropCollection command hasn't yet replicated:
there's still a file on the secondary.

Author: ajdavis

test/test_gridfs.py

@@ -441,7 +441,7 @@ def test_gridfs_secondary_lazy(self):
             _connect=False)
 
         # Still no connection.
-        fs = gridfs.GridFS(client.pymongo_test, _connect=False)
+        fs = gridfs.GridFS(client.test_gridfs_secondary_lazy, _connect=False)
 
         # Connects, doesn't create index.
         self.assertRaises(NoFile, fs.get_last_version)