Only log as info when we can not create a new DB user

Signed-off-by: Joas Schilling <coding@schilljs.com>

lib/private/Setup/MySQL.php

@@ -152,7 +152,7 @@ class MySQL extends AbstractDatabase {
 				};
 			}
 		} catch (\Exception $ex) {
-			$this->logger->error('Specific user creation failed: {error}', [
+			$this->logger->info('Can not create a new MySQL user, will continue with the provided user: {error}', [
 				'app' => 'mysql.setup',
 				'error' => $ex->getMessage()
 			]);