zuul: revert label back to all lower case
Revert "Workaround Zuul normalizing approval fields"
This reverts commit 369e6eb9f3ab57d5ae574dda0113511e970e24b6.
Revert "zuul: fix Gerrit labels"
This reverts commit 4e31d4a94297a49146fc186a9c4c8b6b6f9f47ac.
Require Zuul package 2.0.0-327-g3ebedde-wmf3precise1 which revert an
upstream patches that changed the way labels are passed to the gerrit
review command.
Bug: T106531
Change-Id: Ida64dd26c1e7f1f8254f00451c14263072bc69b7