Remove a comment that's not really correct

Socket.Close is virtually identical to Socket.Dispose.

Author: michaelklishin

projects/client/RabbitMQ.Client/src/client/impl/TcpClientAdapter.cs

@@ -41,7 +41,6 @@ public virtual async Task ConnectAsync(string host, int port)
 
         public virtual void Close()
         {
-            // TODO: Socket.Close() would be a better option here. MK.
             this.Dispose();
         }