Fix missing new-post entries from Special:Contribitions

For Special:Contributions, we're querying for:

    ... rev_user_id = <id> AND rev_user_ip IS NULL ...

new-post (the changetype for creating a new topic) kept adding the username in
rev_user_ip, causing those not to show up.

Change-Id: Ib2624bc229fdc5ea524d88318995bc53a9c496d0
Merge "Fix missing new-post entries from Special:Contribitions"