Skip mechanic update for Combo Challenge

tetris/modes/combo_challenge.lua

@@ -80,9 +80,7 @@ function ComboChallenge:hold(inputs, ruleset, ihs)
 	if ihs then playSE("ihs")
 	else playSE("hold") end
 	self:onHold()
-    if not self.grid:canPlacePiece(self.piece) then
-        self.game_over = true
-    end
+    self:onEnterOrHold(inputs, ruleset)
 end
 
 function ComboChallenge:advanceOneFrame()