Fix multiple pref issues (#18083)

* fix tail alyering pref

* .

* .

* .

* .

* -

* return

* fix that

* write needs save after

* urg

* ban slot change mid round

* -

* .

* properly save

* .

* queue to ss

* read current

* performance

* .

* .

* bit better optimized

* no resetsploit

* this works at least but is it proper (#13)

* this works at least but is it proper

* Update changeling.dm

* this too...

* dont be private

* fix asset ss

---------

Co-authored-by: C.L. <killer65311@gmail.com>

code/controllers/subsystems/character_setup.dm

@@ -37,4 +37,6 @@ SUBSYSTEM_DEF(character_setup)
 			return
 
 /datum/controller/subsystem/character_setup/proc/queue_preferences_save(var/datum/preferences/prefs)
+	if(!prefs)
+		return
 	save_queue |= prefs