fix the aerial caravan migration

migrations/2.1.10.lua

@@ -3,7 +3,25 @@ local function exists_and_valid(v) return v and v.valid end
 if not global.caravans then return end
 local found = false
 local new = {}
+local migrated = 0
+
 for _, caravan_data in pairs(global.caravans) do
+	if caravan_data.is_aerial and script.active_mods.pyalternativeenergy then
+		local entity = caravan_data.entity
+		local _, player = next(game.connected_players)
+		player = player or game.players[1]
+		entity.surface.create_entity{
+			name = entity.name,
+			position = player.position,
+			force = entity.force_index,
+			player = player,
+			create_build_effect_smoke = false,
+			raise_built = true
+		}
+		if entity.valid then entity.destroy() end
+		migrated = migrated + 1
+	end
+
 	if caravan_data.is_aerial
 	or not caravan_data.unit_number
 	or not caravan_data.entity
@@ -21,4 +39,8 @@ end
 global.caravans = new
 if found then
 	global.caravan_queue = nil
+end
+
+if migrated > 0 then
+	game.print('Failed to migrate ' .. migrated .. ' aerial turbines into the new system. Since I\'m so nice, I teleported all of them to your position. Make sure to mine them and place them back so they actually work.')
 end