use finite wait_for_outputs

IPython/parallel/client/asyncresult.py

@@ -158,7 +158,7 b' class AsyncResult(object):'
                 self._success = True
             finally:
                 self._metadata = map(self._client.metadata.get, self.msg_ids)
-                self._wait_for_outputs()
+                self._wait_for_outputs(10)