core/assets: don't set as true the restart argument when not passed

imperium-porcorum.love/core/modules/assets/animator.lua

@@ -76,9 +76,8 @@ end
 function Animator:changeAnimation(name, restart)
   self.currentAnimation   = name
   self.animationData      = self.sprite.data.animations[self.currentAnimation]
-  local restart = restart or true
 
-  if (restart) then
+  if (restart == true) then
     self.frame      = self.animationData.startAt
     self.frameTimer = 0
   end