mate-utils: update to 1.22.1

NB this release has added Inkscape as a tool dependency. (Upstream has
also now excluded a file that was causing itstool failures.)

### mate-utils 1.22.1

    tx: sync with transifex
    Fix -Werror=cast-function-type with GCC 8
    mate-disk-usage-analyzer: Memory leak
    GEN png icons from svg files
    Update documenters in about dialog
    mate-dictionary: Use g_strjoin to build license text
    Use program-name and title in gtk_show_about_dialog call
    help: update copyright

(gutteridge)