something is nil when setting service UUID to ServiceUUIDGenericAccess

Trying the battery example, and changing the service's UUID to `bluetooth.ServiceUUIDGenericAccess`, seems to throw this error upon running:
```
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x0 pc=0xe04c8a]
```
I have no idea what causes this, and it works fine for literally every other service UUID.