AMQP connection failure leads collectd to use 100%CPU

AMQP connection failure leads collectd to use 100%CPU

Summary:
Issue : https://ipm.bloomberg.com/jira/browse/SS-103
Solution : When amqp connection fails, it retries for every message, added a fix to retry only after a delay. A new configuration "ConnectionRetryDelay"  has been introduced with default value as 60 seconds.

Test Plan:
1. Tested without the new configuration
2. Tested with the new configuration

In both the cases, verified connection is retried only after the delay and made sure collectd is not taking 100% cpu.

Reviewers: skhajamo

Reviewed By: skhajamo

CC: arcyd
Differential Revision: https://all.phab.dev.bloomberg.com/D149956

Conflicts:
	src/amqp.c