`$topic_author` may be incorrect after the 'bbp_new_topic_pre_insert' filter

[dd32]

If you use the bbp_new_topic_pre_insert filter to change the authorship of a post (See ​https://meta.trac.wordpress.org/ticket/6839 for a use-case) the following bbp_new_topic hook will fire with the incorrect data passed.

This is because the hook uses the data from before the filter was run.

As a workaround, one can simply use bbp_get_topic_author_id( $topic_id ) instead of the passed $topic_author of the function.

Note: This applies equally to replies.

I've set the severity to minor, as although it's not ideal, this is not overly unexpected.