New install File Server monitor incorrect

short description

On a new install, the $conf['services']['file'] variable may be set incorrectly.

the variable is initially set using dist/conf/*.conf.php (current line 143)
then the variable is set to false a little later in install.php (current line 251)
when apache is selected for the web_server, the variable is set to true without checking for the presence of pure-ftpd (current line 312)
when nginx is selected for the web_server, the variable is not changed at all, so will remain false even if pure-ftpd is installed and working (current line 314)
In either case, the Monitor File Server status may be incorrect; a manual setting is required to correct the monitor process

$conf['services']['file'] should be set to true when pure-ftpd is present and false when it is not regardless of which web_server is selected
$conf['services']['file'] should be set to true when pure-ftpd is forced to be configured during the expert configuration to serve as a reminder to the sysadmin to see that it gets installed correctly

ISPConfig version: Since 3.1

Edited Nov 13, 2020 by Jon Reese