GEOS-Chem submod update: PR #2352 post-merge fix (rebuild KPP files)

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

acd335486 PR #2352 post-merge fix: Rebuild fullchem solver files

This PR restores the updated KPP solver files for PR #2352 (ALK4 and
R4N2 chemistry updates, by @JFBrewer).

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