Clearing displayed_dive here makes no sense for two reasons:
1) This is only called on startup, when displayed_dive is not
yet initialized.
2) The tab-widgets don't use displayed_dive anyway.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>