fix(library/unifier): bug in conflict resolution
fix(library/unifier): bug in conflict resolution

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

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