Calls MainWindow::refreshDisplay() if a dive site was edited so that
the filter lists are updated. The old call to updateDiveInfo() was
removed because it is call implicitly in MainWindow::refreshDisplay()
anyway.
Fixes#675.
Requested-by: Stefan Fuchs <sfuchs@gmx.de>
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>