message: Allow contentType to be undefined in upload sign handler
diff: @@ -10,9 +10,9 @@ function logError(...args: any[]) {
  router.post('/storage/upload/sign', express.json(), async (req, res) => {
  const { contentType } = req.body;
  - if (typeof contentType !== 'string') {
  + if (typeof contentType !== undefined && typeof contentType !== 'string') {
  res.statusCode = 400;
  - res.json({ error: 'Expected contentType to be passed in body' });
  + res.json({ error: 'Expected contentType param to be missing or a string' });
  return;
  }
  