Trying to edit a domain in Froxlor 0.10, I end up with a 500 error. The Apache error log says:
```
[Fri Dec 28 14:44:26.521632 2018] [php7:error] [pid 27116] [client 83.248.199.185:62145] PHP Fatal error: Uncaught Error: Access to undeclared static property: Froxlor\\UI\\HtmlForm::$_form in /var/www/froxlor.0-10/lib/Froxlor/UI/HtmlForm.php(52) : eval()'d code:1\nStack trace:\n#0 /var/www/froxlor.0-10/lib/Froxlor/UI/HtmlForm.php(52): eval()\n#1 /var/www/froxlor.0-10/admin_domains.php(630): Froxlor\\UI\\HtmlForm::genHTMLForm(Array)\n#2 {main}\n thrown in /var/www/froxlor.0-10/lib/Froxlor/UI/HtmlForm.php(52) : eval()'d code on line 1, referer: https://froxlor.fasterminds.com/admin_domains.php?page=domains&s=1c0e3a2e7e88e9eeeb66e5c0efc09ab7
```