[BUG] Adding or deleting custom launch arguments does not save

[jeremybosma]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior:

1. Go to game settings
2. Create a launch argument and click enter
3. Close and open game settings
4. See that it's gone Same goes for removing one you had already made on 0.2.0 where it did work.

Expected behavior It should save.

[guitaripod]

@jeremybosma plz remove me as assignee on all 5 tickets including this one. i can't do that myself :)

[jeremybosma]

@jeremybosma plz remove me as assignee on all 5 tickets including this one. i can't do that myself :)

No problem, really hate to see you leave. Was really appreciating your work and especially the pace.