Only add CPU ranks to gempak CFP file when needed

The gempak j-job was always adding the CPU ranks to the CFP command
file. These are only needed (or allowed) on slurm, which prevented
the job from running properly on WCOSS2. Following the paradigm of
existing jobs, now the ranks are only added if `$CFP_MP` is "YES".

jobs/JGFS_ATMOS_GEMPAK

@@ -104,9 +104,11 @@ echo "time ${SRCgfs}/exgfs_atmos_nawips.sh gfs35_atl 180 GFS_GEMPAK_WWB &> ${DAT
 echo "time ${SRCgfs}/exgfs_atmos_nawips.sh gfs40 180 GFS_GEMPAK_WWB &> ${DATA}/gfs40.$$.1 " >>poescript
 echo "time ${SRCgfs}/exgfs_atmos_nawips.sh gfs40 180 GFS_GEMPAK_WWB &> ${DATA}/gfs40.$$.2 " >>poescript
 
-# Add task number to the MPMD script
-nl -n ln -v 0 poescript > poescript.new
-mv poescript.new poescript
+if [[ ${CFP_MP:-"NO"} == "YES" ]]; then
+  # Add task number to the MPMD script
+  nl -n ln -v 0 poescript > poescript.new
+  mv poescript.new poescript
+fi
 
 cat poescript