GEOS-Chem submod update: Merge PR #2363 (Update setCommonRunSettings.sh)

This commit informs the GCClassic superproject about the following
commits that were pushed to the GitHub geoschem/geos-chem repository:

8554d3a30 Merge PR #2363 (Update setCommonRunSettings.sh.template)

This PR implements a hotfix for an issue where GCHP simulations always
"thought" that they were using mass fluxes regardless of the met field
option chosen.

Signed-off-by: Bob Yantosca <yantosca@seas.harvard.edu>