Error on the 'Files' tab

### Step 1: Please describe your environment

* ZeroNet version: 0.6.1 r3229, Python 2.7.14 (default, Jan 5 2018, 10:41:29)
[GCC 7.2.1 20171224], Gevent: 1.2.2
* Operating system: ArchLinux
* Web browser: Chromium 64.0.3282.140 (Developer Build) (64-bit)
* Tor status: always
* Opened port: no
* Special configuration: -

### Step 2: Describe the problem:
Got the following error every time opening 'Files' tab on ZeroHello:
```
[12:11:16] Site:1HeLLo..Tf3D WebSocket handleRequest error: AttributeError: 'bool' object has no attribute 'get' in UiWebsocket.py line 81 > UiWebsocket.py line 254 > UiWebsocketPlugin.py line 134 > UiWebsocketPlugin.py line 47
{"cmd":"optionalFileList","params":{"address":"all","filter":"downloaded,bigfile","limit":101,"orderby":"time_downloaded DESC"},"wrapper_nonce":"6ed98bb38f0a33bbe7200f7d4487073d0b720e060515167206294d964ce40e0c","id":36}
```

#### Steps to reproduce:

1. Open the 'Files' tab on ZeroHello.

#### Observed Results:


#### Expected Results:

Errorlessness.