
Currently rabbit_retry_interval=0 is internally translated to rabbit_retry_interval=1, which may hide wrong expectation by operators. Add minimum boundary to make sure the given value is valid and is used actually. Also set the minimum boundary for backoff and max as well, to reject too small values or even negative value which may cause malfunction. Change-Id: Iaef2f3c52d6475742dd06c76dfeaebc1c7691d9a