Order posts by dateline

The post_ids in my mybb installation did not be in the right order. Post
with ID 2 was posted after post 5. I think it has something to do with a
previous import from phpbb to mybb.

script/import_scripts/mybb.rb

@@ -94,7 +94,7 @@ class ImportScripts::MyBB < ImportScripts::Base
           FROM mybb_posts p,
                mybb_threads t
          WHERE p.tid = t.tid
-      ORDER BY id
+      ORDER BY p.dateline
          LIMIT #{BATCH_SIZE}
         OFFSET #{offset};
       ")