Fixed MongoDB update error

[kakakakakku]

Hi, thank you for good application 👍

What

I found that some error occurred when editing task at Amazon Lightsail.

  app:utilController attempting to connect to database at mongodb://tasks:tasks@localhost:27017/?authMechanism=SCRAM-SHA-1&authSource=tasks +1s
  app:editController MongoError: the update operation document must contain atomic operators.
  app:editController     at Function.create (/home/bitnami/todo/node_modules/mongodb-core/lib/error.js:43:12)
  app:editController     at toError (/home/bitnami/todo/node_modules/mongodb/lib/utils.js:149:22)
  app:editController     at checkForAtomicOperators (/home/bitnami/todo/node_modules/mongodb/lib/operations/collection_ops.js:176:12)
  app:editController     at Collection.findOneAndUpdate (/home/bitnami/todo/node_modules/mongodb/lib/collection.js:1554:15)
  app:editController     at exports.commitEdit (/home/bitnami/todo/controllers/editController.js:24:31)
  app:editController     at <anonymous>
  app:editController     at process._tickCallback (internal/process/next_tick.js:189:7) +6ms

So, I fixed findOneAndUpdate parameter correctly.

• https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndUpdate/
• https://docs.mongodb.com/manual/reference/operator/update/

Please review it 👍