Fix unbound PS1 message from module-setup

Turns off unbound variable checking when calling `module reset` on
Hera and Orion to supress message about PS1 being unbound since
correcting it is outside the control of workflow.

Resolves #1780

ush/module-setup.sh

@@ -15,15 +15,19 @@ elif [[ ${MACHINE_ID} = hera* ]] ; then
         source /apps/lmod/lmod/init/bash
     fi
     export LMOD_SYSTEM_DEFAULT_MODULES=contrib
+    set +u
     module reset
+    set -u
 
 elif [[ ${MACHINE_ID} = orion* ]] ; then
     # We are on Orion
     if ( ! eval module help > /dev/null 2>&1 ) ; then
         source /apps/lmod/init/bash
     fi
     export LMOD_SYSTEM_DEFAULT_MODULES=contrib
+    set +u
     module reset
+    set -u
 
 elif [[ ${MACHINE_ID} = s4* ]] ; then
     # We are on SSEC Wisconsin S4