import-checker: allow relative import a module being checked This would make the checker more friendly for 3rd-party code. For example, In remotefilelog/x.py, it may have: from . import shallowutils That could trigger "relative import of stdlib module" if "remotefilelog" was installed in the system. If the module being checked conflicts with the system module, it makes sense to not treat that module as system module. This patch makes it so. Differential Revision: https://phab.mercurial-scm.org/D552