fix: log error on missing required fields when finding with fields selection

[onhate]

fix #532

[mobsense]

Thank you!

[revmischa]

What should I do if I add a new required field but still have old objects in my DB which lack a value for that field? Now this is giving me errors for those objects.

[mobsense]

The code will emit a log message but will otherwise work. The alternative is worse where you can have items that don't match the schema and it will return the items silently. This patch addresses that issue.

You can set the {noerror: true} param to suppress the message in 2.7.5.

The real solution is to do a migration to update old items that now don't match the schema.