GEOS-Chem submod update: Merge PR #2326 (GCHP rundir improvements)

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

e0e6e2fb0 Merge PR #2326 (GCHP run directory fixes and improvements)

This PR adds fixes to ExtData.rc for lightning climatology, and
descriptive comments and configuration checks in GCHP run directory
creation scripts.

Signed-off-by: Bob Yantosca <[email protected]>