Do not update _lastChanged on auto-detected attributes

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

Author: come-nc

apps/user_ldap/lib/Configuration.php

@@ -257,6 +257,7 @@ public function readConfiguration(): void {
 	 */
 	public function saveConfiguration(): void {
 		$cta = array_flip($this->getConfigTranslationArray());
+		$changed = false;
 		foreach ($this->unsavedChanges as $key) {
 			$value = $this->config[$key];
 			switch ($key) {
@@ -286,9 +287,12 @@ public function saveConfiguration(): void {
 			if (is_null($value)) {
 				$value = '';
 			}
+			$changed = true;
 			$this->saveValue($cta[$key], $value);
 		}
-		$this->saveValue('_lastChange', (string)time());
+		if ($changed) {
+			$this->saveValue('_lastChange', (string)time());
+		}
 		$this->unsavedChanges = [];
 	}