Fixed JoinedServer event not being raised

src/Discord.Net/API/Servers.cs

@@ -52,7 +52,7 @@ namespace Discord.API
 		[JsonProperty("voice_states")]
 		public VoiceMemberInfo[] VoiceStates;
 		[JsonProperty("unavailable")]
-		public bool Unavailable;
+		public bool? Unavailable;
 	}
 
 	//Create

src/Discord.Net/DiscordClient.cs

@@ -317,7 +317,7 @@ namespace Discord
 							_privateUser.GlobalUser.Update(data.User);
                             foreach (var model in data.Guilds)
 							{
-								if (!model.Unavailable)
+								if (model.Unavailable != true)
 								{
 									var server = _servers.GetOrAdd(model.Id);
 									server.Update(model);
@@ -337,15 +337,12 @@ namespace Discord
 					case "GUILD_CREATE":
 						{
 							var data = e.Payload.ToObject<GuildCreateEvent>(_serializer);
-							if (!data.Unavailable)
-							{
-								var server = _servers.GetOrAdd(data.Id);
-								server.Update(data);
-								if (data.Unavailable == false)
-									RaiseServerAvailable(server);
-								else
-									RaiseJoinedServer(server);
-							}
+							var server = _servers.GetOrAdd(data.Id);
+							server.Update(data);
+							if (data.Unavailable == false)
+								RaiseServerAvailable(server);
+							else
+								RaiseJoinedServer(server);
 						}
 						break;
 					case "GUILD_UPDATE":