Extra check on login page for PHP>=8.0

[forthommel]

Check case if $_SERVER global variable does not contain the REMOTE_USER key. (spotted when updated php from 7.4 to 8.0)

[PGtheG]

This feature should be merged soon. Its a little fix, which could prevent flooding of logs.
I've manually changed this line already to:

if ($this->getConf('showNavbar') === 'logged' && !isset($_SERVER['REMOTE_USER'])) {

[forthommel]

Hello all,
We'll soon reach the 2yrs milestone for this open PR :) what shall we organise for its celebration?

[forthommel]

Thanks, @giterlizzi !