Add a setting "disable_udp_hole_punch" to disable UDP hole punch function (#291)

It can solve #289 tentative.

Co-authored-by: 3rdnature <root@natureblog.net>

easytier/src/easytier-core.rs

@@ -266,6 +266,13 @@ struct Cli {
     )]
     disable_p2p: bool,
 
+    #[arg(
+        long,
+        help = t!("core_clap.disable_udp_hole_punching").to_string(),
+        default_value = "false"
+    )]
+    disable_udp_hole_punching: bool,
+
     #[arg(
         long,
         help = t!("core_clap.relay_all_peer_rpc").to_string(),