Migrate the auth method of OSM user to trust

After some deliberation with the toolserver community, seems like
keeping the status quo of allowing a specific user with only read
privileges and the trust mechanism as a viable option. This will allow
for users to connect without a password only from the labs space.
I already tested this in labs and it will provide no extra privileges
to users (and it will not allow different users and/or different
database connections)

Change-Id: I6f6d84c175567bd30558a43c0ecba79e09bb2512