remove mushroom override now that it's in default

compatibility.lua

@@ -15,13 +15,6 @@ minetest.override_item("default:apple", {
 		leafdecay = 3, leafdecay_drop = 1}
 })
 
-if minetest.registered_nodes["flowers:mushroom_brown"] then
-minetest.override_item("flowers:mushroom_brown", {
-	light_source = 1,
-	groups = {food_mushroom = 1, snappy = 3, attached_node = 1, flammable = 2}
-})
-end
-
 --= Aliases
 
 -- Banana