MPAS-O init mode does not produce error if wrong case requested

In init mode, if you request a test case that does not exist with the flag `config_init_configuration`, it does not produce an error during the init mode, and presumably variables are just filled in with zeros. During the simulation the run will die on start up.

See https://github.com/MPAS-Dev/compass/pull/8#issuecomment-727212984