Increasing xwayland DPI on hotplug

When plugging/unplugging outputs, the xwayland DPI value increases. For instance on my machine it starts at 96, and after plugging an output:

```
> xdpyinfo | grep dots
  resolution:    114x114 dots per inch
```

If I unplug it:

```
> xdpyinfo | grep dots
  resolution:    131x131 dots per inch
```

This may be an xwayland bug.