BUG: Fix error in connection to SSH Proxy

The SSH connector erroneously started a connection to the final destination host, instead of the intended proxy (or jump) host. Fix this error to prevent an infinite recursion.

Author: JoostJM

src/Renci.SshNet/Connection/SshConnector.cs

@@ -24,12 +24,13 @@ public SshConnector(IServiceFactory serviceFactory, ISocketFactory socketFactory
 
         public override Socket Connect(IConnectionInfo connectionInfo)
         {
-            if (connectionInfo == null)
-                throw new ArgumentNullException("connectionInfo");
-            if (connectionInfo.GetType() != typeof(ConnectionInfo))
+            var proxyConnection = connectionInfo.ProxyConnection;
+            if (proxyConnection == null)
+                throw new ArgumentNullException("connectionInfo.ProxyConnection");
+            if (proxyConnection.GetType() != typeof(ConnectionInfo))
                 throw new ArgumentException("Expecting connectionInfo to be of type ConnectionInfo");
 
-            _jumpSession = new Session((ConnectionInfo)connectionInfo, ServiceFactory, SocketFactory);
+            _jumpSession = new Session((ConnectionInfo)proxyConnection, ServiceFactory, SocketFactory);
             _jumpSession.Connect();
             _jumpChannel = new JumpChannel(_jumpSession, connectionInfo.Host, (uint)connectionInfo.Port);
             return _jumpChannel.Connect();