Handle the case where post count is zero. Send 404 header since act_display_404 won't be called. Fixes ticket #854.
Handle the case where post count is zero. Send 404 header since act_display_404 won't be called. Fixes ticket #854.

git-svn-id: d0e296eae3c99886147898d36662a67893ae90b2@3233 653ae4dd-d31e-0410-96ef-6bf7bf53c507

dragonmantank/Habari,dragonmantank/Habari,dragonmantank/Habari