nixos/v2ray: change the type of `config` field

Currently, the type of `config` is `types.attrsOf types.unspecified`. It results
that the merging of list doesn't perform as expected.

For example, I declare two part of config in two files:

`a.nix`:
```
config = {
  routing = {
    rules = [
      {
        type = "field";
        outboundTag = "direct";
        domain = [ "geosite:cn" ];
      }
    ];
  };
};
```

`b.nix`:
```
config = {
  routing = {
    rules = [
      {
        type = "field";
        outboundTag = "direct";
        ip = [
          "geoip:cn"
          "geoip:private"
        ];
      }
    ];
  };
};
```

After merging, only the content of `b.nix` left, the content of `a.nix` is
removed.

This commit give the right type of config, which makes the merging of config
acts as expected.

0 files changed, 0 insertions, 0 deletions