changeset comment: fix delete button issue

issue:
when deleting comments in a list of comments on the same line,
sometimes the add new comment button stops working

root cause:
when deleting a comment in a list of comments that are all on the same line,
the wrong previous tr is chosen, the chosen tr could be an inline comments
instead of a line tr, resulting in the fact that injectinlineform function
will return immediatly

solution:
loop over the found tr until its no longer an inline comment

remark:
could probably be optimised futher to immediatly search for the line tr object