Squashed 'src/machinetalk/proto/' changes from 5a1f48a..48406c8

48406c8 machinetalk-protobuf: fixed wrong enum

git-subtree-dir: src/machinetalk/proto
git-subtree-split: 48406c86ab87cee9d0f66334232c648b50907fd1
Merge commit '9f36f6fe2508268e7dbcd8a85f3de1deb3d54328' into machinetalk-preview-strahlex