Ensure translated pages are rendered with data from master

Possible fix for bug 46716. I can't reproduce it myself so
I can't test the fix either.

Hypothesis: the filter loads page existence data from slave.
Completely new translation would show up as non-existing and
be filtered out. Loading the actual content from master in
the next line would not help, as we already filtered that unit
away. By switching these lines we immediately load the content
and page existence from master and filter afterwads.

Bug: 46716
Change-Id: I5e71c7adf87c1a6ee953d9292965a9231c0299c9
Merge "Ensure translated pages are rendered with data from master"