The procd based init setup uses a custom `pidfile` parameter, but the
used MODEMMANAGER_PID_FILE was not being defined anywhere.
Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>
The bearer status wasn't being loaded in key/value mode, and therefore
would always fail to load the IPv4 config method.
Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>