[Fix] Incorrect json model for Guild Scheduled Event (#2813)

* fix some cringe

* whoooooooops

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

@@ -1,9 +1,6 @@
 using Newtonsoft.Json;
+
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace Discord.API
 {
@@ -16,7 +13,7 @@ namespace Discord.API
         [JsonProperty("channel_id")]
         public Optional<ulong?> ChannelId { get; set; }
         [JsonProperty("creator_id")]
-        public Optional<ulong> CreatorId { get; set; }
+        public Optional<ulong?> CreatorId { get; set; }
         [JsonProperty("name")]
         public string Name { get; set; }
         [JsonProperty("description")]

src/Discord.Net.Rest/Entities/Guilds/RestGuildEvent.cs

@@ -92,7 +92,7 @@ namespace Discord.Rest
                 Creator = RestUser.Create(Discord, model.Creator.Value);
             }
 
-            CreatorId = model.CreatorId.ToNullable() ?? 0; // should be changed?
+            CreatorId = model.CreatorId.GetValueOrDefault(null) ?? 0; // should be changed?
             ChannelId = model.ChannelId.IsSpecified ? model.ChannelId.Value : null;
             Name = model.Name;
             Description = model.Description.GetValueOrDefault();