Randomize user-agent

```
[09:10:28] <BiggieJon> so they seem to be blocking the useragent or IP
[09:11:20] <antomatic> I don't think it's IP
[09:12:40] <antomatic> Yes, user-agent
[09:13:15] <antomatic> the UA the script uses specifically blocked
[09:13:18] <antomatic> no UA is fine
[09:13:35] <antomatic> clarification: no, or different, UA is fine
```