Resolutions selector don't work in print

When added and try to change the scale, the tool sends anyway the wrong scale to print service (probably the map's one). 

Configured as following: 
```
{
     "name": "Print",
     "cfg": {
       "useFixedScales": true,
       "mapPreviewOptions": {
            "enableScalebox": true,
            "enableRefresh": false
       }
     }

```