x11-toolkits/libxaw3dxft: Update 1.6.2h => 1.6.4, transfer maintainership

Changelogs:
https://github.com/DaveFlater/libXaw3dXft/releases/tag/v1.6.3
https://github.com/DaveFlater/libXaw3dXft/releases/tag/v1.6.4

Upstream moved from SF to github.
While here pet portclippy.

PR: 288964
Approved by: pyrus@bsdmail.com (former maintainer)
Co-authored-by: Vladimir Druzenko <vvd@FreeBSD.org>