modules.services.xray.server: set serverName default to xserver2

devices/vps4/default.nix

@@ -28,7 +28,7 @@ inputs:
       {
         sshd = {};
         fail2ban = {};
-        xray.server.serverName = "xserver.vps4.chn.moe";
+        xray.server = {};
       };
     };
   };

modules/services/xray.nix

@@ -33,7 +33,7 @@ inputs:
     {
       type = types.nullOr (types.submodule { options =
       {
-        serverName = mkOption { type = types.nonEmptyStr; };
+        serverName = mkOption { type = types.nonEmptyStr; default = "xserver2.chn.moe"; };
       };});
       default = null;
     };