A number of settings in the `debugger` group were wrongly using a newly
constructed `QSettings` object instead of the singleton object that
`GetQSettings()` provides.
This made the application create a spurious, extra configuration file in
the user directory:
```
~/.config/Dolphin Emulator/dolphin-emu.conf
```
Notice that, by default, the application configuration files are stored
in `~/.config/dolphin-emu`; not in `~/.config/Dolphin Emulator`.