am ece784c5: Fix error in InefficientWeight rule. It would wrongly assume 0dip != 0dip.

Merge commit 'ece784c583edbbeb56e8a74d4ddf039121d0df71' into eclair-mr2

* commit 'ece784c583edbbeb56e8a74d4ddf039121d0df71':
  Fix error in InefficientWeight rule. It would wrongly assume 0dip != 0dip.