don't let explosions destroy sign entities

signs/compatibility.lua

@@ -61,9 +61,11 @@ minetest.register_lbm({ name = "signs:conpatibility_1",
 -- We need to have this entity registered to be able to remove it.
 if minetest.registered_entities["signs:text"] == nil then
 	minetest.register_entity("signs:text", {
-		collisionbox = { 0, 0, 0, 0, 0, 0 },
-		visual = "upright_sprite",
-		textures = {},
+		on_activate = function(self)
+			if self.object then
+				self.object:remove()
+			end
+		end
 	})
 end