fix: Team is nullable, not optional (#1672)

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

@@ -20,7 +20,7 @@ namespace Discord.API
         [JsonProperty("bot_require_code_grant")]
         public bool BotRequiresCodeGrant { get; set; }
         [JsonProperty("team")]
-        public Optional<Team> Team { get; set; }
+        public Team Team { get; set; }
 
         [JsonProperty("flags"), Int53]
         public Optional<ulong> Flags { get; set; }

src/Discord.Net.Rest/Entities/RestApplication.cs

@@ -59,8 +59,8 @@ namespace Discord.Rest
                 Flags = model.Flags.Value; //TODO: Do we still need this?
             if (model.Owner.IsSpecified)
                 Owner = RestUser.Create(Discord, model.Owner.Value);
-            if (model.Team.IsSpecified && model.Team.Value != null)
-                Team = RestTeam.Create(Discord, model.Team.Value);
+            if (model.Team != null)
+                Team = RestTeam.Create(Discord, model.Team);
         }
 
         /// <exception cref="InvalidOperationException">Unable to update this object from a different application token.</exception>