Exceptions can occur during configure_connection and can be retried.

https://bugzilla.redhat.com/show_bug.cgi?id=1120364

Add "connection not open" as another retryable connection exception.

Reported and patched by Carsten Clasohm
Merge pull request #4 from jrafanie/vendored_3_2_17

Exceptions can occur during configure_connection and can be retried.