GEOS-Chem submod update: Merge PR #2402 (Fixes for HEMCO_Diagn.rc)

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

34507531 Merge PR #2402 (Fixes for HEMCO_Diagn.rc)

This PR adds 2 fixes:

1. Use offline biogenic MOH emissions (except for the benchmark simulation,
   which uses online emissions by default)

2. Auto-set GCHP emissions sources in HEMCO_Diagn.rc based on HEMCO_Config.rc.

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