style(lua): add missing include
style(lua): add missing include

Signed-off-by: Leonardo de Moura <7610bae85f2b530654cc716772f1fe653373e892@microsoft.com>

eigengrau/lean,fpvandoorn/lean2,fgdorais/lean,leodemoura/lean,leodemoura/lean,rlewis1988/lean,levnach/lean,leanprover-community/lean,leanprover/lean,sp3ctum/lean,leanprover/lean,johoelzl/lean,leanprover/lean,UlrikBuchholtz/lean,Kha/lean,fgdorais/lean,soonhokong/lean-osx,digama0/lean,dselsam/lean,eigengrau/lean,fgdorais/lean,rlewis1988/lean,fpvandoorn/lean2,johoelzl/lean,dselsam/lean,fgdorais/lean,htzh/lean,avigad/lean,soonhokong/lean-osx,levnach/lean,leanprover/lean,leanprover-community/lean,javra/lean,soonhokong/lean,leodemoura/lean,soonhokong/lean-windows,digama0/lean,levnach/lean,fgdorais/lean,Kha/lean,htzh/lean,digama0/lean,digama0/lean,levnach/lean,avigad/lean,soonhokong/travis_test,leodemoura/lean,soonhokong/lean,Kha/lean,levnach/lean,avigad/lean,c-cube/lean,leodemoura/lean,avigad/lean,soonhokong/travis_test,fpvandoorn/lean,rlewis1988/lean,sp3ctum/lean,soonhokong/lean,fgdorais/lean,soonhokong/lean-windows,UlrikBuchholtz/lean,soonhokong/travis_test,fpvandoorn/lean2,fpvandoorn/lean,johoelzl/lean,UlrikBuchholtz/lean,UlrikBuchholtz/lean,soonhokong/lean-osx,codyroux/lean0.1,johoelzl/lean,htzh/lean,javra/lean,johoelzl/lean,eigengrau/lean,fpvandoorn/lean,rlewis1988/lean,fpvandoorn/lean2,dselsam/lean,sp3ctum/lean,dselsam/lean,dselsam/lean,fpvandoorn/lean2,soonhokong/lean,eigengrau/lean,digama0/lean,c-cube/lean,fpvandoorn/lean,soonhokong/lean-windows,htzh/lean,c-cube/lean,Kha/lean,sp3ctum/lean,javra/lean,fpvandoorn/lean,Kha/lean,c-cube/lean,dselsam/lean,leanprover-community/lean,fpvandoorn/lean,codyroux/lean0.1,soonhokong/lean-osx,soonhokong/lean,leodemoura/lean,soonhokong/lean-osx,c-cube/lean,leanprover/lean,UlrikBuchholtz/lean,leanprover-community/lean,leanprover-community/lean,codyroux/lean0.1,avigad/lean,sp3ctum/lean,htzh/lean,javra/lean,avigad/lean,rlewis1988/lean,codyroux/lean0.1,soonhokong/travis_test,leanprover-community/lean,digama0/lean,leanprover/lean,javra/lean,Kha/lean,johoelzl/lean,soonhokong/lean-windows,soonhokong/lean-windows,rlewis1988/lean,eigengrau/lean