Update payu/models/cesm_cmeps.py

Co-authored-by: Aidan Heerdegen <[email protected]>

payu/models/cesm_cmeps.py

@@ -251,7 +251,7 @@ def _setup_checks(self):
                     case _:
                         raise ValueError(
                             f"The iotype for {io_section} in {NUOPC_CONFIG} is "
-                            'invalid, valid options are "netcdf", "pnetcdf" and "netcdf4p"'
+                            'invalid, valid options: "netcdf", "pnetcdf", "netcdf4p"'
                         )
         return True