D552: import-checker: allow relative import a module being checked

[quark (Jun Wu)]

quark added inline comments.

INLINE COMMENTS

> ryanmce wrote in test-imports-checker.t:128
> Shallow? Do you mean "allow"?

Good catch. Should be "shadowing". Will change.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D552

To: quark, #hg-reviewers
Cc: ryanmce, mercurial-devel