app_server just passes the add-on path around.
Maybe we should make sure the add-on can be loaded when setting it.
Change-Id: I3acd3299782a22c1666bd5435dbf3d8053e359fa
Reviewed-on: https://review.haiku-os.org/c/1430
Reviewed-by: waddlesplash <waddlesplash@gmail.com>