Fix python 3.6 compatibility issue
See: https://github.com/mperezi/hadolint-wrapper/commit/8dd652302155e624a09329b5b9f005f3a0766689
Closes: https://gitlab.freedesktop.org/hadess/power-profiles-daemon/-/issues
Signed off: James Dominic P. Guana jdpguana@histark.com