Bug 53182: Don't show new pages editor for newly created pages

When a page doesn't exist we need to refresh the article id so the
editor no longer sees it as new.

Using -1 as a workaround as API doesn't contain id

Change-Id: I0a23e0188b7bf25dbbed4b4fe62419497afee6b9
Merge "Bug 53182: Don't show new pages editor for newly created pages"