fix thread member nre (#1977)

src/Discord.Net.Rest/API/Common/ThreadMember.cs

@@ -14,12 +14,6 @@ namespace Discord.API
         [JsonProperty("join_timestamp")]
         public DateTimeOffset JoinTimestamp { get; set; }
 
-        [JsonProperty("presence")]
-        public Optional<Presence> Presence { get; set; }
-
-        [JsonProperty("member")]
-        public Optional<GuildMember> Member { get; set; }
-
         [JsonProperty("flags")]
         public int Flags { get; set; } // No enum type (yet?)
     }

src/Discord.Net.WebSocket/DiscordSocketClient.cs

@@ -2529,15 +2529,13 @@ namespace Discord.WebSocket
                                         {
                                             SocketGuildUser guildMember;
 
-                                            if (threadMember.Member.IsSpecified)
+                                            guildMember = guild.GetUser(threadMember.UserId.Value);
+
+                                            if(guildMember == null)
                                             {
-                                                guildMember = guild.AddOrUpdateUser(threadMember.Member.Value);
+                                                await UnknownGuildUserAsync("THREAD_MEMBERS_UPDATE", threadMember.UserId.Value, guild.Id);
                                             }
                                             else
-                                            {
-                                                guildMember = guild.GetUser(threadMember.UserId.Value);
-                                            }
-
                                                 newThreadMembers.Add(thread.AddOrUpdateThreadMember(threadMember, guildMember));
                                         }
 

src/Discord.Net.WebSocket/Entities/Users/SocketThreadUser.cs

@@ -137,16 +137,6 @@ namespace Discord.WebSocket
         internal void Update(Model model)
         {
             ThreadJoinedAt = model.JoinTimestamp;
-
-            if (model.Presence.IsSpecified)
-            {
-                GuildUser.Update(Discord.State, model.Presence.Value, true);
-            }
-
-            if (model.Member.IsSpecified)
-            {
-                GuildUser.Update(Discord.State, model.Member.Value);
-            }
         }
 
         /// <inheritdoc/>