Adds params field to BlockingConnection object

It is needed for pika_pool library which expects that
connections has params attribute defined in BaseConnection
 but BlockingConnection is not derived from BaseConnection
 and doesn't have it

Change-Id: Ic86c4c4e929c53c116e73242b5f71aa1ec7d3d07

oslo_messaging/_drivers/pika_driver/pika_engine.py

@@ -311,6 +311,13 @@ class PikaEngine(object):
         :return: New connection
         """
 
+        connection_params = pika.ConnectionParameters(
+            heartbeat_interval=(
+                self._heartbeat_interval if for_listening else None
+            ),
+            **self._connection_host_param_list[host_index]
+        )
+
         with self._connection_lock:
             cur_time = time.time()
 
@@ -333,20 +340,18 @@ class PikaEngine(object):
                 )
 
             try:
-                base_host_params = self._connection_host_param_list[host_index]
-
                 connection = pika.BlockingConnection(
-                    parameters=pika.ConnectionParameters(
+                    parameters=connection_params,
-                        heartbeat_interval=(
-                            self._heartbeat_interval
-                            if for_listening else None
-                        ),
-                        **base_host_params
-                    ),
                     _impl_class=(_create_select_poller_connection_impl
                                  if self._force_select_poller_use else None)
                 )
 
+                # It is needed for pika_pool library which expects that
+                # connections has params attribute defined in BaseConnection
+                # but BlockingConnection is not derived from BaseConnection
+                # and doesn't have it
+                connection.params = connection_params
+
                 self._set_tcp_user_timeout(connection._impl.socket)
 
                 self._connection_host_status_list[host_index][