If we leave ratbagctl.devel too soon, ratbagd gets killed before it even
receives the async call for commmit(), meaning everything we do on the
device is lost.
0.5 is empirical. It seems on my system 0.2 is enough (0.1 doesn't seem
to work). Hopefully this value is not device dependent.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>