Alter pong packet to conform to the spec.

SharpChat/Packet/PongPacket.cs

@@ -4,20 +4,8 @@ using System.Text;
 
 namespace SharpChat.Packet {
     public class PongPacket : ServerPacket {
-        public DateTimeOffset PongTime { get; private set; }
-
-        public PongPacket(DateTimeOffset dto) {
-            PongTime = dto;
-        }
-
         public override IEnumerable<string> Pack() {
-            StringBuilder sb = new();
-
-            sb.Append('0');
-            sb.Append('\t');
-            sb.Append(PongTime.ToUnixTimeSeconds());
-
-            yield return sb.ToString();
+            yield return "0\tpong";
         }
     }
 }

SharpChat/PacketHandlers/PingHandler.cs

@@ -26,7 +26,7 @@ namespace SharpChat.PacketHandlers {
                 return;
 
             ctx.Connection.BumpPing();
-            ctx.Connection.Send(new PongPacket(ctx.Connection.LastPing));
+            ctx.Connection.Send(new PongPacket());
 
             ctx.Chat.ContextAccess.Wait();
             try {