New version of gpb: 4.21.4#177

lrascao merged 2 commits intolrascao:developlrascao/rebar3_gpb_plugin:developfrom

tomas-abrahamsson:pr-for-version-4.21.4tomas-abrahamsson/rebar3_gpb_plugin:pr-for-version-4.21.4Copy head branch name to clipboard