samba: 4.7.10 -> 4.10.2

Release notes: https://www.samba.org/samba/history/samba-4.10.2.html
Notably, Samba 4.10.0 is the first with Python 3 support,
and the 4.10 line will be the last supporting Python 2,
so switch to Python 3.

Add myself as a maintainer.