Remove the comment which is a bit misleading

This fixes #6652.

Rationale

The invocation of initChannel of ChannelInitializer has been moved to as
early as during handlerAdded is invoked in 26aa34853, whereas it was
only invoked during channelRegistered is invoked before that. So the
comment does not describe how handlers are added in normal circumstances
anymore.

However, the code is kept as-is since there might be unusual cases, and
adding ServerBootstrapAcceptor via the event loop is always safe to
enforce the correct order.

transport/src/main/java/io/netty/bootstrap/ServerBootstrap.java

@@ -175,10 +175,6 @@ public class ServerBootstrap extends AbstractBootstrap<ServerBootstrap, ServerCh
                     pipeline.addLast(handler);
                 }
 
-                // We add this handler via the EventLoop as the user may have used a ChannelInitializer as handler.
-                // In this case the initChannel(...) method will only be called after this method returns. Because
-                // of this we need to ensure we add our handler in a delayed fashion so all the users handler are
-                // placed in front of the ServerBootstrapAcceptor.
                 ch.eventLoop().execute(new Runnable() {
                     @Override
                     public void run() {