Make each vacuuming tube only vacuum one entity per second (may help tubes not to break)

vacuum_tubes.lua

@@ -84,7 +84,9 @@ end
 
 local function vacuum(pos, radius)
 	radius = radius + 0.5
+	local trueish = false
 	for _, object in pairs(minetest.get_objects_inside_radius(pos, math.sqrt(3) * radius)) do
+		if trueish == true then return end
 		local lua_entity = object:get_luaentity()
 		if not object:is_player() and lua_entity and lua_entity.name == "__builtin:item" then
 			local obj_pos = object:get_pos()
@@ -98,6 +100,7 @@ local function vacuum(pos, radius)
 					lua_entity.itemstring = ""
 				end
 				object:remove()
+				trueish = true
 			end
 		end
 	end