devel/py-ruamel.yaml: update to 0.19.1
No support implemented yet for ruamel.yaml.clibz in this port --
with 0.19.1 clibz is an optional dependency, and the python code
will prefer the existing ruamel.yaml.clib package if installed.
Changes: https://sourceforge.net/p/ruamel-yaml/code/ci/0.19.1/tree/CHANGES
Reported by: repology