Add USE_OCN_PERTURB_FILES to gfs config.base

Set to .false. by default; needed for staging job

Refs NOAA-EMC#2475

parm/config/gfs/config.base

@@ -437,6 +437,10 @@ export INCVARS_EFOLD="5"
 export netcdf_diag=".true."
 export binary_diag=".false."
 
+# Initialize ocean ensemble members with perturbations
+#   if true, only occurs for members greater than zero
+export USE_OCN_PERTURB_FILES=".false."
+
 # Verification options
 export DO_METP="NO"          # Run METPLUS jobs - set METPLUS settings in config.metp; not supported with spack-stack
 export DO_FIT2OBS="YES"      # Run fit to observations package