removed accidental "$" attribute in json from getZoneAttrs() and getZoneInfo()

Before:
```
{ '$': undefined,
  CurrentZoneName: 'Playroom',
  CurrentIcon: 'x-rincon-roomicon:playroom',
  CurrentConfiguration: '1' }
```

After:
```
{ CurrentZoneName: 'Playroom',
  CurrentIcon: 'x-rincon-roomicon:playroom',
  CurrentConfiguration: '1' }
```