all: add support to Netgear Orbi Voxel

While at it, also ensure checking the service is installed or not before
executing uninstall function, so we won't emit un-necessary errors.

cmd/cli/service.go

@@ -20,7 +20,7 @@ func newService(i service.Interface, c *service.Config) (service.Service, error)
 		return nil, err
 	}
 	switch {
-	case router.IsOldOpenwrt():
+	case router.IsOldOpenwrt(), router.IsNetGearOrbi():
 		return &procd{&sysV{s}}, nil
 	case router.IsGLiNet():
 		return &sysV{s}, nil