Correct system_url() behaviour

[wiredrat78]

Hi team,

I've noticed that, in both the Inara and EDSM plugins, the function system_url() prioritises the current system over the supplied argument.

# noinspection PyUnresolvedReferences
def system_url(system_name: str) -> str:
    """Get a URL for the current system."""
    if this.system_address:
        return requests.utils.requote_uri(f'https://inara.cz/elite/starsystem/'
                                          f'?search={this.system_address}')

    if system_name:
        return requests.utils.requote_uri(f'https://inara.cz/elite/starsystem/'
                                          f'?search={system_name}')

    return ''

It would make more sense if it returns the URL to current system if no arguments is passed. The funcion station_url() actually do this and returns current stations if no arguments are passed. Is it the expected behaviour?