nixos: set stopIfChanged to false (#2105)

There is no ExecStop so we can just restart the service.

(cherry picked from commit 4ed6705b0f)

nixos/default.nix

@@ -130,6 +130,8 @@ in {
 
         unitConfig = { RequiresMountsFor = usercfg.home.homeDirectory; };
 
+        stopIfChanged = false;
+
         serviceConfig = {
           User = usercfg.home.username;
           Type = "oneshot";