allow more complex access-log formats to be displayed correctly on the UI, fixes #1139

Signed-off-by: Michael Kaufmann <d00p@froxlor.org>

actions/admin/settings/130.webserver.php

@@ -181,7 +181,8 @@ return [
 					'label' => lng('serversettings.logfiles_format'),
 					'settinggroup' => 'system',
 					'varname' => 'logfiles_format',
-					'type' => 'text',
+					'type' => (strpos(Settings::Get('system.logfiles_format'), '"') !== false ? 'textarea' : 'text'),
+					'string_regexp' => '/^[^\0\r\n<>]*$/i',
 					'default' => '',
 					'string_emptyallowed' => true,
 					'save_method' => 'storeSettingField',