Get rid of m_consumerLock

m_consumer is volatile + its readers assign it to a local variable
before using it.
Merge bug26122 into default
Added tag rabbitmq_v3_3_1 for changeset ca35272f6df7
stable to default
Merge bug26131
merge default into bug26133
Remove re-connection attempts from BrokerUnreachableException
merge bug26133 into bug26135