add paramter 'mail-notify' to froxlor:update CLI script to notify the system administrator via email about a new version (once per version)

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

install/froxlor.sql.php

@@ -700,6 +700,8 @@ opcache.validate_timestamps'),
 	('system', 'acmeshpath', '/root/.acme.sh/acme.sh'),
 	('system', 'distribution', ''),
 	('system', 'update_channel', 'stable'),
+	('system', 'updatecheck_data', ''),
+	('system', 'update_notify_last', '0.11.0-dev1'),
 	('api', 'enabled', '0'),
 	('2fa', 'enabled', '1'),
 	('panel', 'decimal_places', '4'),

install/updates/froxlor/update_0.11.inc.php

@@ -37,7 +37,10 @@ if (!defined('_CRON_UPDATE')) {
 
 // last 0.10.x release
 if (Froxlor::isFroxlorVersion('0.10.99')) {
-	Update::showUpdateStep("Updating from 0.10.99 to 0.11.0-dev1", false);
+
+	$update_to = '0.11.0-dev1';
+
+	Update::showUpdateStep("Updating from 0.10.99 to ".$update_to, false);
 
 	Update::showUpdateStep("Removing unused table");
 	Database::query("DROP TABLE IF EXISTS `panel_sessions`;");
@@ -134,6 +137,7 @@ if (Froxlor::isFroxlorVersion('0.10.99')) {
 	Settings::AddNew("system.distribution", $system_distribution);
 	Settings::AddNew("system.update_channel", 'stable');
 	Settings::AddNew("system.updatecheck_data", '');
+	Settings::AddNew("system.update_notify_last", $update_to);
 	Update::lastStepStatus(0);
 
 	Update::showUpdateStep("Adjusting existing settings");
@@ -152,5 +156,5 @@ if (Froxlor::isFroxlorVersion('0.10.99')) {
 	Settings::Set('panel.standardlanguage', $lang_map[Settings::Get('panel_standardlanguage')] ?? 'en');
 	Update::lastStepStatus(0);
 
-	Froxlor::updateToVersion('0.11.0-dev1');
+	Froxlor::updateToVersion($update_to);
 }

install/updates/preconfig/preconfig_0.10.inc.php

@@ -23,8 +23,6 @@
  * @license    https://files.froxlor.org/misc/COPYING.txt GPLv2
  */
 
-use Froxlor\Froxlor;
-use Froxlor\FileDir;
 use Froxlor\Install\Update;
 
 $preconfig = [