Improve first steps using the server without setup.

In particular, it could be that the connection string is set to a
default value and actually allows to connect to a database, where our
model has not been deployed yet. In that case we just display the same
no-setup page.
Fix the build queue listing when no animal is registered.

We used to display an empty list in that case, which doesn't reflect at
all on what's happening: we still have items in the queue and we'd
better show'em.