Preserve Objectives when admin-removing antag status

Sometimes admins want to change someone's antag type or simply refresh their antag status to fix bugs, while still preserving their objectives.  Being forced to lose them makes these really frustrating to do!

Admins can still manually remove their objectives from the same window (Mind Window/Traitor Panel).

code/datums/mind.dm

@@ -110,7 +110,6 @@
 			qdel(changeling)
 			changeling = null
 	special_role = null
-	remove_objectives()
 	remove_antag_equip()
 
 /datum/mind/proc/remove_traitor()
@@ -121,7 +120,6 @@
 			A.set_zeroth_law("")
 			A.show_laws()
 	special_role = null
-	remove_objectives()
 	remove_antag_equip()
 
 /datum/mind/proc/remove_nukeop()
@@ -137,7 +135,6 @@
 		ticker.mode.wizards -= src
 		current.spellremove(current)
 	special_role = null
-	remove_objectives()
 	remove_antag_equip()
 
 /datum/mind/proc/remove_cultist()