Cant search with symbols

When I try to find for example `InvSee++` I got:

```
{
  "error": "Unexpected Exception",
  "msg": "Unexpected Exception. Please report this to https://github.com/SpiGetOrg/api.spiget.org/issues"
}%      
```


Steps to reproduce:
`
curl 'https://api.spiget.org/v2/search/resources/InvSee%2B%2B?field=name'     
`