Fix lua error from leaving an active run maybe?

classes/class_combat.lua

@@ -211,7 +211,7 @@ local segmentTypeToString = {
 	---@return boolean
 	---@return number
 	function classCombat:IsMythicDungeon()
-		local bIsMythicPlusSegment = self.is_mythic_dungeon_segment
+		local bIsMythicPlusSegment = self.is_mythic_dungeon and self.is_mythic_dungeon_segment
 		local runId = self.is_mythic_dungeon_run_id
 		return bIsMythicPlusSegment, runId
 	end