sftpgo-auth: check user existence before password

sftpgo-auth.php

@@ -4,7 +4,7 @@ require "router.php";
 
 $authData = json_decode(file_get_contents("php://input"), true);
 
-if (checkPassword($authData['username'], $authData['password']) === true) {
+if (userExist($authData['username']) === true AND checkPassword($authData['username'], $authData['password']) === true) {
 	echo '
 	{
 		"status": 1,