Ignore InterruptedException and continue to check the channel

On the OpenStack Jenkins install we are seeing many occasions
where the InterruptedException from the wait is causing jobs
to fail.

bug report in OpenStack-CI:
https://bugs.launchpad.net/openstack-ci/+bug/1260311

logstash query:
http://bit.ly/1eXPv67

This patch has defensive code to prevent completely giving up
when we run into this InterruptedException