Fix unhandled timeout in OVSDBNettyFactoryIT

The IT sometimes hangs when run due to a timeout in getting the schema.
Limit connection attemtps to 3 seconds with 3 retries.
This does not fix the root cause, but *does* fail the IT.

Change-Id: Ie209fb5cadadd832991dc406133b96e291d38369
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Merge "Fix unhandled timeout in OVSDBNettyFactoryIT"