Requests to URLs like /sso_for_azure_ad/asdasdfasdf/ always show site content

Hello,

Great and simple plugin, thanks.

I noticed the issue which potentialy should be easy to fix.

We found in logs tons of requests to URLs like /sso_for_azure_ad/*/*/*/ …

I tested by my self, and noticed that when I visit the page like /sso_for_azure_ad/some-rundom-string show me the site home page. I expedited it should be 404.

Here is a simple fix for that:

function sso_for_azure_ad_handler_template_include( $template ) {
  global $wp_query;

  $should_stop = false;
  $sso_for_azure_ad_query = $wp_query->get( 'sso_for_azure_ad' );

  if ( $sso_for_azure_ad_query == 'start' ) {
    $should_stop = sso_for_azure_ad_handler_start();
  } elseif ( $sso_for_azure_ad_query == 'callback' ) {
    $should_stop = sso_for_azure_ad_handler_callback();
  }
  else {
    $wp_query->set_404();
    status_header(404);
    get_template_part(404);
    exit('Not found.');
  }

  if ( $should_stop ) {
    exit;
   } else {
    return $template;
  }
}

I am not sure how to contribute back to the WP pluging, looks like wordpress in not realy opensoruce-friendly.

If author can review the code and add it back to the plugin, this would be awesome!

Would be nice if community can review the code also.