Bug when opening change stream with filter matching documents on two diferent collections

[snava10]

Due to an error in the oplog implementation, a change stream opened against a collection would pick up documents from another collection if they match the filter.
The solution is to filter documents from the oplog based on their namespace "."
In this way preventing change streams to pick up documents from collections other than the one being watch.

[bwaldvogel]

Thanks for your contribution!