Add fix for duplicate ready rocket silo

lignumis/scripts/wooden-rocket-silo.lua

@@ -106,7 +106,9 @@ local function on_silo_mined(event)
     local player = game.get_player(event.player_index)
     for i, entry in pairs(storage.rocket_silos) do
         if entry.fake_silo == fake_silo then
+            if entry.real_silo.valid then
                 player.mine_entity(entry.real_silo, true)
+            end
             table.remove(storage.rocket_silos, i)
             break
         end