Remove `pre_get_posts` action `bbp_pre_get_posts_normalize_forum_visibility` from forum visibility repair tool to prevent hidden and private post status injected into WP_Query. Props thebrandonallen. Fixes #2512 

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5257 9866e705-20ec-0310-96e7-cbb4277adcfb