Remove more libraries directives from server

pkg/analysis_server/lib/src/channel/web_socket_channel.dart

Index: pkg/analysis_server/lib/src/channel/web_socket_channel.dart
diff --git a/pkg/analysis_server/lib/src/channel/web_socket_channel.dart b/pkg/analysis_server/lib/src/channel/web_socket_channel.dart
index dc7890127a1494bdabbb9c2ab881aed547068d50..072ab4117956e70b51841fb652fb5e5aae583814 100644
--- a/pkg/analysis_server/lib/src/channel/web_socket_channel.dart
+++ b/pkg/analysis_server/lib/src/channel/web_socket_channel.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library channel.web_socket;
-
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';