JCBC-566: Catch ConfigurationException to prevent IO loop death

When CCCP protocol enabled, there is a likelihood that
ConfigurationException will bubble up and kill the IO loop. When
connectivity will be restored, the client cannot reconnect the nodes.

Change-Id: I52de7e70008cddc602169356d4db0b592bcfb682
Reviewed-on: http://review.couchbase.org/41677
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Tested-by: Matt Ingenthron <matt@couchbase.com>