Skeleton: fix tagged open leafs not being found
Skeleton: fix tagged open leafs not being found

Fix a bug where any tag on a leaf was causing it to be not be returned
by last_openleaf, even if the tag did not indicate ending.

See acardona/CATMAID#884.

fzadow/CATMAID,fzadow/CATMAID,fzadow/CATMAID,fzadow/CATMAID