Fail to import Group project if an belonging project is already imported

[alkalinan]

On Gitlab Importer

When a existing project is imported in the model, than the parent group of this project is load, the import crash on comparing the branches. The error occurs when the branches are added to the model, with no project id is find.

Reproduction code (no token needed) Pharo 12 Moose 12 ; GitProjectHealth main

model := GLHModel new.

importer := GitModelImporter forGitlabWithToken: ''.

project := importer importProject: 79944331.

groupOfThisProject := importer importGroup: 126002108.