Fixed HttpServer.cs

Example3/Example3.csproj

@@ -49,7 +49,6 @@
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
-    <Reference Include="System.Configuration" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AssemblyInfo.cs" />

Example3/Program.cs

@@ -1,7 +1,4 @@
 using System;
-using System.Configuration;
-using System.IO;
-using System.Text;
 using WebSocketSharp;
 using WebSocketSharp.Net;
 using WebSocketSharp.Server;