Cant fresh install using latest LGSL 7

[BaxAndrei]

Describe the bug
Installer is broken in lgsl7

To Reproduce
Steps to reproduce the behavior:
Install fresh copy from latest commit

Expected behavior
Installer work and website is accesible after install

Screenshots
No ss, but after install all my vars in lgs_config are stored wrong like:
$lgsl_config['style'] = '"darken_style.css"';
$lgsl_config['scripts'] = "["parallax.js","preview.js","refresh.js","flag-icon.js",]";

Also if you have special characters in administrator password like " or & json will fail to parse when sending post request