Merge branch '332-modulecmd-use-of-unset-variable-in-sub-cmd-unuse' into 'master'

Resolve "modulecmd: use of unset variable in sub-cmd unuse"

Closes #332

See merge request Pmodules/src!311

(cherry picked from commit 59c116b70b)

fefe313d modulecmd: use of unset variable fixed

Co-authored-by: gsell <achim.gsell@psi.ch>

Pmodules/modulecmd.bash.in

@@ -1993,13 +1993,15 @@ subcommand_unuse() {
 					 "${arg}"
 			fi
 
-                        local var="PMODULES_LOADED_${arg^^}"
-                        if [[ -n "${!var}" ]]; then
-                                std::die 3 "%s %s: %s -- %s" \
-                                         "${CMD}" "${SubCommand}" \
-                                         "cannot remove group due to loaded modules" \
-                                         "${arg}"
-                        fi
+			if [[ -v PMODULES_LOADED_${arg^^} ]]; then 
+				local var="PMODULES_LOADED_${arg^^}"
+				if [[ -n "${!var}" ]]; then
+					std::die 3 "%s %s: %s -- %s" \
+						 "${CMD}" "${SubCommand}" \
+						 "cannot remove group due to loaded modules" \
+						 "${arg}"
+				fi
+			fi
                         std::remove_path UsedGroups "${arg}"
                         local overlay
                         for overlay in "${UsedOverlays[@]}"; do