Honor proxy credentials when setting a SOCKS proxy, close AsyncHttpClient#1509

Motivation:

We don’t currently honor proxy’s Realm when setting a SOCKS proxy.

Modifications:

Pass username and password when creating a Socks(4|5)ProxyHandler.

Result:

Creds honored on SOCKS proxies

Author: slandelle

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

@@ -410,14 +410,17 @@ public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
             @Override
             protected void initChannel(Channel channel) throws Exception {
               InetSocketAddress proxyAddress = new InetSocketAddress(whenProxyAddress.get(), proxy.getPort());
+              Realm realm = proxy.getRealm();
+              String username = realm != null ? realm.getPrincipal() : null;
+              String password = realm != null ? realm.getPassword() : null;
               ProxyHandler socksProxyHandler;
               switch (proxy.getProxyType()) {
                 case SOCKS_V4:
-                  socksProxyHandler = new Socks4ProxyHandler(proxyAddress);
+                  socksProxyHandler = new Socks4ProxyHandler(proxyAddress, username);
                   break;
 
                 case SOCKS_V5:
-                  socksProxyHandler = new Socks5ProxyHandler(proxyAddress);
+                  socksProxyHandler = new Socks5ProxyHandler(proxyAddress, username, password);
                   break;
 
                 default: