graphics/xfig: update to 3.2.8b

ChangeLog: https://sourceforge.net/p/mcj/xfig/ci/master/tree/CHANGES

This update also fixes the build in 14.

BUGS FIXED:
 * Adding points to splines works if boxes are present in the figure.
 * Stay in the working directory when browsing picture files.

PR:		273130
Reported by:	mjl@luckie.org.nz (maintainer)