IOException wrapped in InternalError not handled properly

[PearSlice]

Describe the bug
The call to socket.connect(...) at WebSocketClient:436 can throw a java.lang.InternalError that is currently not handled in the enclosing try/catch as it extends java.lang.Error and not java.lang.Exception

This InternalError wraps a java.lang.IOException that contains useful information to the websocket engine to hande this case.

To Reproduce
Steps to reproduce the behavior:

1. Install a proxy, i.e. squid
2. Make it deny connections

Example application to reproduce the issue
Use the previously installed proxy in the ProxyClientExample

Expected behavior
An IOException handled by the underlying websocket engine

Debug log

Exception in thread "WebSocketConnectReadThread-11" java.lang.InternalError: Should not reach here
	at java.net.HttpConnectSocketImpl.doTunneling(HttpConnectSocketImpl.java:181)
	at java.net.HttpConnectSocketImpl.doTunnel(HttpConnectSocketImpl.java:168)
	at java.net.HttpConnectSocketImpl.access$200(HttpConnectSocketImpl.java:44)
	at java.net.HttpConnectSocketImpl$2.run(HttpConnectSocketImpl.java:151)
	at java.net.HttpConnectSocketImpl$2.run(HttpConnectSocketImpl.java:149)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.HttpConnectSocketImpl.privilegedDoTunnel(HttpConnectSocketImpl.java:148)
	at java.net.HttpConnectSocketImpl.connect(HttpConnectSocketImpl.java:111)
	at java.net.Socket.connect(Socket.java:589)
	at org.java_websocket.client.WebSocketClient.run(WebSocketClient.java:436)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at java.net.HttpConnectSocketImpl.doTunneling(HttpConnectSocketImpl.java:179)
	... 10 more
Caused by: java.io.IOException: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 403 Forbidden"
	at sun.net.www.protocol.http.HttpURLConnection.doTunneling(HttpURLConnection.java:2142)
	... 15 more

Environment(please complete the following information):

• Version used: 1.4.0
• Java version: 1.8.0_181
• Operating System and version: Ubuntu 16.04 LTS
• Endpoint Name and version: "ws://echo.websocket.org"
• Link to your project: ProxyClientExample in the examples folder

Additional context
This is my first time reporting an issue on a open source project.
I'm open to feedback :)

[marci4]

Hello @PearSlice,

thank you for creating this bug report!

Looks good :)

Best regards,
Marcel