fix error with vagrant build
remove submodule of live-build
Squashed 'external/live-build/' content from commit 00939c3

git-subtree-dir: external/live-build
git-subtree-split: 00939c3a2a7882ac0df307b5c0d850f780023cf8
Merge commit '52995cc63720a28dd5cca04156114b5567434bd9' as 'external/live-build'
improve live-build installation?