Crash when typing in machine properties box

**Describe the issue**

Trying to type highmem=off in the properties box just hangs UTM, sometimes I have time to type one character sometimes more. It is fine when pasting it and it allows me to save.
There were no VMs running at that time.

**Configuration**
* UTM Version: 4.0.7 (66)
* macOS Version: 12.6
* Mac Chip (Intel, M1, ...): M1 Max

**Crash log**
No crash report

**Debug log**
VM is not started when doing that.

**Upload VM**
The VM is coming from a previous version (the latest stable whatever that was)
[config.plist.zip](https://github.com/utmapp/UTM/files/9778349/config.plist.zip)