Toby Zerner 01f3a7dc01 Fix bug when loading a single post at the start
When loading a single post at the start of a discussion, start=0 and
end=0. But end would be set to start+limit, which was incorrect.
2015-01-30 12:15:01 +10:30
..
2015-01-21 14:29:00 +10:30
2015-01-21 14:29:00 +10:30