Quadra 800 Emulation Dies with 'RAMBlock "macfb-vram" already registered, abort!'

**Describe the issue**
When launching an m68k virtual machine, configured as "Macintosh Quadra 800 (q800)", the VM immediately terminates with 'RAMBlock "macfb-vram" already registered, abort!' I am using a 1MB ROM from my Quadra, added to the package contents of UTM, under 'contents/resources/qemu', as 'MacROM.bin'.

**Configuration**
* UTM Version: 2.4.0
* OS Version: 11.6
* Apple Silicon

**Crash log**
[QEMULauncher_2021-11-02-084401_odysseus.crash.zip](https://github.com/utmapp/UTM/files/7460730/QEMULauncher_2021-11-02-084401_odysseus.crash.zip)

**Debug log**
[debug.log](https://github.com/utmapp/UTM/files/7460747/debug.log)

**Upload VM**
[config copy.plist.zip](https://github.com/utmapp/UTM/files/7460762/config.copy.plist.zip)