Clear item meta when turning fishbucket to empty bucket

before it simply set a different itemstring, now it creates a
whole new itemstack

mods/ITEMS/mcl_buckets/fishbuckets.lua

@@ -33,7 +33,7 @@ local function on_place_fish(itemstack, placer, pointed_thing)
 				minetest.set_node(pos,{name = water})
 			end
 			if not placer or not minetest.is_creative_enabled(placer:get_player_name()) then
-				itemstack:set_name("mcl_buckets:bucket_empty")
+				itemstack = ItemStack("mcl_buckets:bucket_empty")
 			end
 		end
 	end