Bug: Manifest considers a multipack atlas the same file

[Milton Candelero]

A multipack atlas is exported like this:

    {
      "name": "game",
      "assets": [
        {
          "name": [
            "E.json"
          ],
          "srcs": [
            "game/game-1.json",
            "game/game-0.json"
          ],
          "data": {
            "tags": {
              "tps": true,
              "m": true
            }
          }
        }
      ]
    },

And free-tex-packer doesn't have a multi pack field so Assets only downloads the first json and the rest of the spritesheet is never loaded