[WIP] Fixed issue with reconnect mechanism

When an unexpected error happens when reading frames during the open_connection
method the mechanism failed to kick in and the connection would never be re-established.
Mm I was worried something like that would be the case ;) Unfortunately there is no context available for the code to tell them apart.

Worst case scenario in the older RabbitMQ version an auth exception would result in hammering for Bunny 1.5+.