fix(frontends/lean/elaborator): warning message
fix(frontends/lean/elaborator): warning message

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

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