Use new tsv column in searches

lib/search.rb

@@ -49,7 +49,7 @@ def search_posts(db, query, username, offset)
     FROM posts
     INNER JOIN threads on posts.thread_id = threads.id
     WHERE
-      to_tsvector(body) @@ plainto_tsquery(?)
+      tsv @@ plainto_tsquery(?)
       AND (
         (LOWER(posts.creator) = LOWER(?)) OR (? = '')
       )