In early iterations of the lobby map generation logic, a for loop was
used to retry map generation with alternative seeds in case it
failed. This seed randomization logic didn't exist in the final merged
version, but the for loop wasn't cleanup up, and ends up repeating any
map generation failures 5 times deterministically.
Additionally, the logic caught Exception instead of the more specific
MapGenerationException, which is the only exception that is expected
to arise in healthy builds/configurations (due to bad luck rather than
bugs).
This change:
- removes the for loop;
- only catches MapGenerationException;
- adjusts the user-visible failure message to reflect that trying
again (without adjusting settings) is a valid course of action (now
that it's not done internally);
484784bd4d