support 1.21.2

Author: laz1444

src/MiNET/MiNET/LoginMessageHandler.cs

@@ -530,7 +530,7 @@ public void HandleMcpeClientToServerHandshake(McpeClientToServerHandshake messag
 			IMcpeMessageHandler messageHandler = server.CreatePlayer(_session, _playerInfo);
 			_bedrockHandler.Handler = messageHandler; // Replace current message handler with real one.
 
-			if (_playerInfo.ProtocolVersion != McpeProtocolInfo.ProtocolVersion)
+			if (_playerInfo.ProtocolVersion != McpeProtocolInfo.ProtocolVersion && _playerInfo.ProtocolVersion != McpeProtocolInfo.v1_21_2)
 			{
 				Log.Warn($"Wrong version ({_playerInfo.ProtocolVersion}) of Minecraft. Upgrade to join this server.");
 				_session.Disconnect($"Wrong version ({_playerInfo.ProtocolVersion}) of Minecraft. This server requires {McpeProtocolInfo.ProtocolVersion}");

src/MiNET/MiNET/Net/MCPE Protocol.cs

@@ -44,6 +44,7 @@ namespace MiNET.Net
 	public class McpeProtocolInfo
 	{
 		public const int ProtocolVersion = 685;
+		public const int v1_21_2 = 686;
 		public const string GameVersion = "1.21.0";
 	}