hashindex: fixed iteritems segfaulting with non-existent marker, fixes #9368#9517

ThomasWaldmann merged 1 commit intoborgbackup:1.2-maintborgbackup/borg:1.2-maintfrom

ThomasWaldmann:fix-hashindex-1.2ThomasWaldmann/borg:fix-hashindex-1.2Copy head branch name to clipboard