Prune 21 obsolete ports

FreeBSD Ports maintainers have already deleted the following:
  audio/gsi
  dns/bind96
  french/ispell
  german/ispell
  german/ispell-alt
  german/ispell-neu
  graphics/glfw-devel
  hungarian/ispell
  multimedia/kino
  polish/gimp-help
  polish/ispell
  portuguese/ispell-pt_BR
  russian/rus-ispell
  sysutils/mbmon
  textproc/british-ispell
  textproc/es-ispell
  textproc/ispell
  textproc/it-ispell
  textproc/nl-ispell
  textproc/sk-ispell
  ukrainian/ispell
Update ports-mgmt/pkg to version 1.2.6
Tweak misc/mime-support version 3.54
Update devel/ccache to version 3.1.9_4
Tweak misc/gnomehier version 3.0
Tweak sysutils/gnome_subr version 1.0
Tweak databases/qdbm version 1.8.78
Tweak misc/hicolor-icon-theme version 0.12
Tweak security/mhash version 0.9.9.9_1