ZeroNet should not check for open port when using --tor always

```
./zeronet.py --tor always
```

```
- Starting ZeroNet...
[23:14:14] - OpenSSL loaded, version: 01000206F
[23:14:14] - Patching sockets to tor socks proxy: 127.0.0.1:9050
[23:14:14] - Version: 0.3.6 r949, Python 2.7.11+ (default, Feb 22 2016, 16:38:42)
[GCC 5.3.1 20160220], Gevent: 1.0.1
[23:14:15] - Creating FileServer....
[23:14:15] - Creating UiServer....
[23:14:15] - Removing old SSL certs...
[23:14:15] - Starting servers....
[23:14:15] Ui.UiServer --------------------------------------
[23:14:15] Ui.UiServer Web interface: http://127.0.0.1:43110/
[23:14:15] Ui.UiServer --------------------------------------
[23:14:25] FileServer Checking port 15441 using portchecker.co...
```

When we want to always use Tor, there is no need to check for an open port. Let alone opening a port. That should be avoided.

Start with the ./zeronet.py --tor always entry point and follow the startup path through the FileServer port check. Confirm the behavior with Tor-only startup, then ensure this mode neither checks for an open port nor attempts to open one.

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