Improve BrokerConnection initialization (dpkp#1475)

Author: romulorosa

kafka/conn.py

@@ -949,9 +949,9 @@ def check_version(self, timeout=2, strict=False):
             selector = self.config['selector']()
             selector.register(self._sock, selectors.EVENT_READ)
             while not (f.is_done and mr.is_done):
+                selector.select(1)
                 for response, future in self.recv():
                     future.success(response)
-                selector.select(1)
             selector.close()
 
             if f.succeeded():