Update src/killsw

src/killsw

@@ -17,8 +17,8 @@ case "$cmd" in
         systemctl status killswitch.target
         ;;
     add)
-        if [[ -n "$2" && "$3" == "to" && -n "$5" ]]; then
-            echo "Called add $2 to $5"
+        if [[ -n "$2" && "$3" == "to" && -n "$4" ]]; then
+            echo "Called add $2 to $4"
         else
             echo "Usage: killsw add [service] to [group]"
         fi