Remove unnecessary call for REST if user didn't specify the bool

src/Discord.Net.Rest/Entities/Channels/ChannelHelper.cs

@@ -22,7 +22,6 @@ namespace Discord.Rest
 
         public static async Task<Model> ModifyAsync(IGuildChannel channel, BaseDiscordClient client,
             Action<GuildChannelProperties> func,
-            IEnumerable<Overwrite> overwrites,
             RequestOptions options)
         {
             var args = new GuildChannelProperties();
@@ -31,14 +30,16 @@ namespace Discord.Rest
             {
                 Name = args.Name,
                 Position = args.Position,
-                CategoryId = args.CategoryId,
-                Overwrites = args.SyncWithParent.Value
-                    ? overwrites
-                        .Select(overwrite => new API.Overwrite(overwrite.TargetId, overwrite.TargetType,
-                            overwrite.Permissions.AllowValue, overwrite.Permissions.DenyValue))
-                        .ToArray()
-                    : null
+                CategoryId = args.CategoryId
             };
+            if (args.SyncWithParent.IsSpecified && args.SyncWithParent.Value)
+            {
+                var categoryChannel = await channel.GetCategoryAsync().ConfigureAwait(false);
+                apiArgs.Overwrites = categoryChannel.PermissionOverwrites
+                    .Select(overwrite => new API.Overwrite(overwrite.TargetId, overwrite.TargetType,
+                        overwrite.Permissions.AllowValue, overwrite.Permissions.DenyValue))
+                    .ToArray();
+            }
             return await client.ApiClient.ModifyGuildChannelAsync(channel.Id, apiArgs, options).ConfigureAwait(false);
         }
         public static async Task<Model> ModifyAsync(ITextChannel channel, BaseDiscordClient client,

src/Discord.Net.Rest/Entities/Channels/RestGuildChannel.cs

@@ -58,8 +58,7 @@ namespace Discord.Rest
         }
         public async Task ModifyAsync(Action<GuildChannelProperties> func, RequestOptions options = null)
         {
-            var categoryChannel = await GetCategoryAsync().ConfigureAwait(false);
-            var model = await ChannelHelper.ModifyAsync(this, Discord, func, categoryChannel.PermissionOverwrites, options).ConfigureAwait(false);
+            var model = await ChannelHelper.ModifyAsync(this, Discord, func, options).ConfigureAwait(false);
             Update(model);
         }
         public Task DeleteAsync(RequestOptions options = null)

src/Discord.Net.WebSocket/Entities/Channels/SocketGuildChannel.cs

@@ -58,7 +58,7 @@ namespace Discord.WebSocket
         }
 
         public Task ModifyAsync(Action<GuildChannelProperties> func, RequestOptions options = null)
-            => ChannelHelper.ModifyAsync(this, Discord, func, Category.PermissionOverwrites, options);
+            => ChannelHelper.ModifyAsync(this, Discord, func, options);
         public Task DeleteAsync(RequestOptions options = null)
             => ChannelHelper.DeleteAsync(this, Discord, options);