Install missing WebSocketClientCompressionHandler when using HTTP proxy + wss, close #1689

 Motivation:

WebSocketClientCompressionHandler is only installed on the no proxy path.

Modification:

Install WebSocketClientCompressionHandler on the proxy path too.

Result:

WebSocket compression work when using a proxy too.

Author: slandelle

client/src/main/java/org/asynchttpclient/netty/channel/ChannelManager.java

@@ -353,6 +353,11 @@ public Future<Channel> updatePipelineForHttpTunneling(ChannelPipeline pipeline,
 
     if (requestUri.isWebSocket()) {
       pipeline.addAfter(AHC_HTTP_HANDLER, AHC_WS_HANDLER, wsHandler);
+
+      if (config.isEnableWebSocketCompression()) {
+        pipeline.addBefore(AHC_WS_HANDLER, WS_COMPRESSOR_HANDLER, WebSocketClientCompressionHandler.INSTANCE);
+      }
+
       pipeline.remove(AHC_HTTP_HANDLER);
     }
     return whenHanshaked;