Roll recipe dependencies (trivial).

This is an automated CL created by the recipe roller. This CL rolls recipe
changes from upstream projects (e.g. depot_tools) into downstream projects
(e.g. tools/build).


More info is at https://goo.gl/zkKdpD. Use https://goo.gl/noib3a to file a bug.
recipe_engine:
  https://crrev.com/51e6ae23f698f81136bc508f633588354b5969ca Revert of [autoroller] All commits in updates(), only roll interesting ones. (patchset #2 id:20001 of https://codereview.chromium.org/2829203002/ ) (iannucci@chromium.org)


TBR=iannucci@chromium.org

Change-Id: I0a9170310569057b5bd261089ecd8ee301c19965
Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Reviewed-on: https://chromium-review.googlesource.com/484079
Reviewed-by: <recipe-roller@chromium.org>
Commit-Queue: <recipe-roller@chromium.org>

infra/config/recipes.cfg

@@ -15,7 +15,7 @@
   "deps": {
     "recipe_engine": {
       "branch": "master",
-      "revision": "763b5442fe13969bc3ffc0fa37bcc527fa9814bf",
+      "revision": "51e6ae23f698f81136bc508f633588354b5969ca",
       "url": "https://chromium.googlesource.com/external/github.com/luci/recipes-py.git"
     }
   },