Adds Nar-Sie Hologram and Backup Error Screen to AI

Allows the AI the ability to use the holographic Nar-Sie sprite from the
selection. Also adds in a backup error screen for the AI in the case the
icon text is incorrect when the variable is changed.

code/modules/mob/living/silicon/ai/ai.dm

@@ -814,7 +814,8 @@ var/list/ai_verbs_default = list(
 		var/icon_list[] = list(
 		"default",
 		"floating face",
-		"xeno queen"
+		"xeno queen",
+		"eldritch"
 		)
 		input = input("Please select a hologram:") as null|anything in icon_list
 		if(input)
@@ -826,6 +827,8 @@ var/list/ai_verbs_default = list(
 					holo_icon = getHologramIcon(icon('icons/mob/AI.dmi',"holo2"))
 				if("xeno queen")
 					holo_icon = getHologramIcon(icon('icons/mob/AI.dmi',"holo3"))
+				if("eldritch")
+					holo_icon = getHologramIcon(icon('icons/mob/AI.dmi',"holo4"))
 	return
 
 /mob/living/silicon/ai/proc/corereturn()