Due to relaxation of when last paragraph of commit message is
is consider as containing footers, `git cl land` started removing
non-canonic footer lines from last paragraph if Git Numberer is enabled
on a repo. This only manifests in manual lands of Rietveld CLs or
bypassing code review entirely.

R=agable@chromium.org
Bug: 736852
Change-Id: I3972c590c3959974157ada9de9891a3c08bd385a
Reviewed-on: https://chromium-review.googlesource.com/562278Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>