fix(library/module_mgr): do not cause waits for preimported modules
fix(library/module_mgr): do not cause waits for preimported modules

fgdorais/lean,dselsam/lean,leanprover-community/lean,fpvandoorn/lean,fgdorais/lean,dselsam/lean,digama0/lean,fpvandoorn/lean,johoelzl/lean,johoelzl/lean,Kha/lean,leanprover/lean,dselsam/lean,leodemoura/lean,Kha/lean,rlewis1988/lean,avigad/lean,leanprover-community/lean,dselsam/lean,digama0/lean,digama0/lean,digama0/lean,fpvandoorn/lean,fpvandoorn/lean,leanprover/lean,fpvandoorn/lean,fgdorais/lean,fgdorais/lean,johoelzl/lean,rlewis1988/lean,avigad/lean,rlewis1988/lean,rlewis1988/lean,leanprover-community/lean,avigad/lean,johoelzl/lean,digama0/lean,leanprover-community/lean,dselsam/lean,leodemoura/lean,leanprover/lean,fgdorais/lean,avigad/lean,rlewis1988/lean,fgdorais/lean,dselsam/lean,avigad/lean,johoelzl/lean,leanprover-community/lean,digama0/lean,leodemoura/lean,rlewis1988/lean,leodemoura/lean,leanprover/lean,leodemoura/lean,leodemoura/lean,johoelzl/lean,avigad/lean,Kha/lean,Kha/lean,Kha/lean,fpvandoorn/lean,leanprover-community/lean,Kha/lean,leanprover/lean,leanprover/lean