fix nbd mispelling in /etc/modules
Merge pull request #617 from blueboxgroup/modules-nbd-fixup-for-master

fix nbd mispelling in /etc/modules
Flush swift handlers before service start

Flushing the handlers means non-running services will get started, and
then the task to ensure the service is running will be unchanged.
Without flushing handlers a scenario can happen that will result in a
service being started and then immediately restarted.

fixes #595