Change GSI tag to gfsda.v16.1.0

The GSI tag has been updated for the v16.1 implementation.  This
implementation turns on commercial RO data from GeoOptics.  See
release notes docs/Release_Notes.gfs.v16.1.0.txt in the global-workflow
and release notes doc/Release_Notes.gfsda.v16.1.0.txt in the GSI for
details.

Refs: #301

sorc/checkout.sh

@@ -38,7 +38,7 @@ if [[ ! -d gsi.fd ]] ; then
     rm -f ${topdir}/checkout-gsi.log
     git clone --recursive https://github.com/NOAA-EMC/GSI.git gsi.fd >> ${topdir}/checkout-gsi.log 2>&1
     cd gsi.fd
-    git checkout gfsda.v16.0.0
+    git checkout gfsda.v16.1.0
     git submodule update
     cd ${topdir}
 else