Send heartbeat frames more often

The AMQP protocol is saying that we should send "two"
"heartbeat frames" during the "heartbeat timeout" (see [1] and rabbit
implement this in [2]).

The "two" value is the "rate" parameter in the current implementation.

The current implementation was sending only one frame during the
"heartbeat timeout", which is wrong.

[1] https://www.amqp.org/specification/0-9-1/amqp-org-download
[2] https://www.rabbitmq.com/heartbeats.html#heartbeats-interval

Signed-off-by: Arnaud Morin <arnaud.morin@ovhcloud.com>

Author: arnaudmorin

amqp/connection.py

@@ -754,7 +754,7 @@ def heartbeat_tick(self, rate=2):
         self.prev_sent, self.prev_recv = sent_now, recv_now
 
         # send a heartbeat if it's time to do so
-        if now > self.last_heartbeat_sent + self.heartbeat:
+        if now > self.last_heartbeat_sent + self.heartbeat / rate:
             AMQP_HEARTBEAT_LOGGER.debug(
                 'heartbeat_tick: sending heartbeat for connection %s',
                 self._connection_id)