Missing Update for Meteor 3.0

[nesbtesh]

This line is missing update for Meteor 3.0

https://github.com/meteor/meteor/blob/c38e3c7f3834cb20e8f4cc0473a9011091301778/packages/accounts-base/accounts_server.js#L455C5-L455C94

[denihs]

I'm not sure from which branch this commit is, but in the current release-3.0 branch, this already uses findOneAsync.