Spurius isStub

[Damien Cassou]

When generating the mse from epyf (evitech/sp1/exemple), we get a stub module for some code in the project

(FAMIX.PyModule (id: 8)
  (name 'epyf.core.shell')
  (isStub true)
)

Beyons remove the isStub, there should be an isPackage