Fix list permission and user command

src/Service/DatabaseService.php

@@ -111,8 +111,9 @@ class DatabaseService
         }
     }
 
-    public function listPermissions(string $user, ?string $host = 'localhost'): array
+    public function listPermissions(string $user, ?string $host = null): array
     {
+        $host ??= 'localhost';
         $results = $this->conn->query(sprintf("SHOW GRANTS FOR '%s'@'%s'", $user, $host), );
 
         $permissions = [];