Define an environment variable to be accessible by qvm-sync-appmenus

[ma...@lamarciana.com]

Hi,

I'm working in a small pull request to Qubes which modifies `/etc/qubes-rpc/qubes.GetAppmenus` to, optionally, read something from an environment variable.

The issue is that, while manually testing it, I find no way to set an environment variable from my VM making it accessible when `qvm-sync-appmenus` is run. No matter in which shell initialization file I set it, it isn't read.

Where should I set that environment variable to make sure that scripts like `qvm-sync-appmenus` will load it?

Thanks