Unexpected deletion of the keyPrefix option

Created by: nekocode

Description

In latest code, the instantiation of queue will deleted keyPrefix property of the options object which we passed to the second function parameter:

if (_.isString(url)) {
  // ...
} else {
  opts = url || {};
}

// ...

delete opts.redis.keyPrefix;

It causes that we will loss the keyPrefix if we use one options instance to initialize multiple queues.

I think we should use a deep cloned options object to make sure the passed one will not be changed.

Minimal, Working Test code to reproduce the issue.

I wrote a test to reproduce the issue: https://github.com/nekocode/bull/commit/06feb3176c85891b7180b72ea7c20d3a4514c089

it('should not change the options object', async () => {
  const originalOptions = { redis: { keyPrefix: 'myQ' } };
  const options = _.cloneDeep(originalOptions);

  let queue = new Queue('q', 'redis://127.0.0.1', options);
  expect(_.isEqual(options, originalOptions)).to.be.true;
  await queue.close();

  queue = new Queue('q', options);
  expect(_.isEqual(options, originalOptions)).to.be.true;
  await queue.close();
});

Bull version

3.22.9 (latest)