setting a max DB connect timeout of 1 second for pulp-manage-db

If a user runs pulp-manage-db while mongo is not listening for connections,
that user does not want the usual retry back-off. They want pulp-manage-db to
keep trying about once per second until a connection is established.

I can't find any tests for the ``initialize`` function, and I don't want to block this tiny improvement on having to write a whole set of tests. This area is going to get re-worked this sprint anyway when mongoengine is dropped in.