This mysterious IgnoreDeleteRedlines flag was set in this particular
case of a new DELETE redline inside or equal to an existing INSERT
redline since initial import.

Why it's needed is documented nowhere.

If it is needed, then i'm assuming it's only needed to prevent
deleting redlines that are actually in the pNewRedl range;
it makes no sense to prevent deletion of redlines inside a footnote
when that footnote is deleted, because there is no valid
position left for such redlines.

The problem here is that in the range that is deleted there is a
footnote and there is another redline inside the footnote text
and that has its positions corrected rather ridiculously by
DelBookmarks() because DeleteRedline() ignored it due to the flag.

Remove the call to MaybeNotifyRedlineModification(), to fix a
SwTiledRenderingTest::testRedlineUpdateCallback failure,
assuming that it is only called to compensate for the flag
being set, seeing as this is the only such call in AppendRedline.

Change-Id: I0f266213b8525f7bee06ee0d56290f4524bf0d85
Reviewed-on: https://gerrit.libreoffice.org/46016Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>