Fix mark_when setter

mark_when was not taken in consideration.

app/Models/ConfigurationSetter.php

@@ -210,11 +210,9 @@ class FreshRSS_ConfigurationSetter {
 
 	private function _mark_when(&$data, $values) {
 		foreach ($values as $key => $value) {
-			if (isset($data['mark_when'][$key])) {
 			$data['mark_when'][$key] = $this->handleBool($value);
 		}
 	}
-	}
 
 	private function _onread_jump_next(&$data, $value) {
 		$data['onread_jump_next'] = $this->handleBool($value);