Highlander will not be activated if admins exit the highlander delay window. (#74400)

## About The Pull Request

Starting highlander as an admin prompts admins if they want it to start
with or without a warning. If you exit the window it treats it as if you
selected the 40 second warning. This makes it so admins can now cancel
out of this window.
## Why It's Good For The Game

Sometime, somewhere and admin is going to accidently click this button
and be unable to stop the unintended incoming highlander round. This
should prevent this.
## Changelog
🆑
admin: Exiting the highlander delay window without selecting an option
will no longer start highlander mode.
/🆑

code/modules/admin/verbs/secrets.dm

@@ -43,6 +43,7 @@ GLOBAL_DATUM(everyone_a_traitor, /datum/everyone_is_a_traitor_controller)
 	return data
 
 #define THUNDERDOME_TEMPLATE_FILE "admin_thunderdome.dmm"
+#define HIGHLANDER_DELAY_TEXT "40 seconds (crush the hope of a normal shift)"
 /datum/secrets_menu/ui_act(action, params)
 	. = ..()
 	if(.)
@@ -260,11 +261,14 @@ GLOBAL_DATUM(everyone_a_traitor, /datum/everyone_is_a_traitor_controller)
 		if("onlyone")
 			if(!is_funmin)
 				return
-			var/response = tgui_alert(usr,"Delay by 40 seconds?", "There can, in fact, only be one", list("Instant!", "40 seconds (crush the hope of a normal shift)"))
-			if(response == "Instant!")
-				holder.only_one()
-			else
-				holder.only_one_delayed()
+			var/response = tgui_alert(usr,"Delay by 40 seconds?", "There can, in fact, only be one", list("Instant!", HIGHLANDER_DELAY_TEXT))
+			switch(response)
+				if("Instant!")
+					holder.only_one()
+				if(HIGHLANDER_DELAY_TEXT)
+					holder.only_one_delayed()
+				else
+					return
 			SSblackbox.record_feedback("nested tally", "admin_secrets_fun_used", 1, list("There Can Be Only One"))
 		if("guns")
 			if(!is_funmin)
@@ -588,6 +592,7 @@ GLOBAL_DATUM(everyone_a_traitor, /datum/everyone_is_a_traitor_controller)
 	if(holder)
 		log_admin("[key_name(holder)] used secret [action]")
 #undef THUNDERDOME_TEMPLATE_FILE
+#undef HIGHLANDER_DELAY_TEXT
 
 /proc/portalAnnounce(announcement, playlightning)
 	set waitfor = FALSE