In certain circumstances (running msfconsole as a normal user with sudo, no web browser open) `xdg-open` will block until the user closes the browser.  This causes msfconsole to appear frozen.  Pressing `ctrl+c` in msfconsole, causes the browser to close.  This is probably not what we want.

I'd recommend spawning the xdg-open command instead of using system:

    pid = ::Process.spawn(cmd, "https://localhost:3790")
    ::Process.detach(pid)

Doing it this way may need some additional error handling, not sure.