Avoid moving retry to next host when request ID == 0

Fixes PYTHON-88

CHANGELOG.rst

@@ -5,6 +5,7 @@ In Progress
 Bug Fixes
 ---------
 * Properly specify UDTs for columns in CREATE TABLE statements
+* Avoid moving retries to a new host when using request ID zero (PYTHON-88)
 
 Other
 -----

cassandra/cluster.py

@@ -2558,7 +2558,7 @@ class ResponseFuture(object):
             # to retry the operation
             return
 
-        if reuse_connection and self._query(self._current_host):
+        if reuse_connection and self._query(self._current_host) is not None:
             return
 
         # otherwise, move onto another host