lib/prefs/permission.php, site.php contain untranslateable text

• Consistency
• Less than 30-minutes fix
• Easy for Newbie Dev

In lib/prefs/permission.php is a help text that resists all trials to translate it. It does get pumped through tra(), but I cannot translate it even if I copy exactly the string from the PHP source code. I have also tried to substitute the line break that is contained by \n, the newline character. To no avail.

The code in question is this:

function prefs_permission_list()
{
	return [
		'permission_denied_url' => [
			'name' => tra('Send to URL'),
			'description' => tra('URL to redirect to on "permission denied"'),
			'type' => 'text',
			'size' => '50',
			'default' => '',
			'tags' => ['basic'],
		],
		'permission_denied_login_box' => [
			'name' => tra('On permission denied, display login module'),
			'description' => tra('If an anonymous visitor attempts to access a page for which permission is not granted, Tiki will automatically display the Log-in module. 
Alternatively, use the Send to URL field to display a specific page (relative to your Tiki installation) instead.'),
			'type' => 'flag',
			'default' => 'n',
			'tags' => ['basic'],
		],
	];
}

The string in 'description' cannot be translated. And when I grep through the entirety of Tiki 18.6, in no language has anyone managed to translate this part, because in all of the 58 languages that are available in /lang, not a single one custom.php or language.php contains a string starting with "If an anonymous visitor"...

This bug has been demonstrated on show2.tikiwiki.org

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