Fixed numeric terms in topN query

If terms are numeric (like 1 or 0), error is generated:

```
TypeError: Object 1 has no method 'replace'
    at Object.kbn.addslashes (file:///Users/bobrik/projects/kibana/src/app/components/kbn.js:198:15)
   <skipped>
```

@rashidkpc, also look at `src/app/services/querySrv.js:140`, you left some debugging there :)