Don't stall when failing to create SslHandler, close AsyncHttpClient#1361

Motivation:

Creating a SslHandler can crash, for example when there's a typo in the
enabled protocols.
When this happens, the exception is not propagated.

Modification:

Catch such Exception and notify the NettyConnectListener.

Result:

AHC no longer stalled when such exception happens.

Author: slandelle

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

@@ -110,7 +110,13 @@ public void onSuccess(Channel channel, InetSocketAddress remoteAddress) {
 
         // in case of proxy tunneling, we'll add the SslHandler later, after the CONNECT request
         if (future.getProxyServer() == null && uri.isSecured()) {
-            SslHandler sslHandler = channelManager.addSslHandler(channel.pipeline(), uri, request.getVirtualHost());
+            SslHandler sslHandler = null;
+            try {
+                sslHandler = channelManager.addSslHandler(channel.pipeline(), uri, request.getVirtualHost());
+            } catch (Exception sslError) {
+                NettyConnectListener.this.onFailure(channel, sslError);
+                return;
+            }
 
             final AsyncHandlerExtensions asyncHandlerExtensions = toAsyncHandlerExtensions(future.getAsyncHandler());