Set the proper port on the remote channel.

Without this fix, GDB tries to connect to the gdbserver on the SSH port
when using the "Attach to Running Application" action. This fixes that
to use the proper gdbserver port.

Change-Id: I4ada31693879f28acf8046885d1dd15aff5d748c
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>

src/plugins/debugger/gdb/startgdbserverdialog.cpp

@@ -209,6 +209,7 @@ void GdbServerStarter::attach(int port)
     QTC_ASSERT(fillParameters(&sp, d->kit), return);
     sp.masterEngineType = GdbEngineType;
     sp.connParams.port = port;
+    sp.remoteChannel = sp.connParams.host + QLatin1Char(':') + QString::number(sp.connParams.port);
     sp.displayName = tr("Remote: \"%1:%2\"").arg(sp.connParams.host).arg(port);
     sp.executable = localExecutable;
     sp.startMode = AttachToRemoteServer;