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
(or complain)

recipe_engine:
  https://crrev.com/4e4e32822f4b0aab38308d0d5c7b6561268702ed [protos] Regenerate protos and add documentation. (iannucci@chromium.org)

TBR=martiniss@chromium.org

Change-Id: I6606c679ed6bebeba47881e398727bd8618a43db
Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Reviewed-on: https://chromium-review.googlesource.com/452159
Reviewed-by: <recipe-roller@chromium.org>
Commit-Queue: <recipe-roller@chromium.org>

infra/config/recipes.cfg

@@ -5,5 +5,5 @@ deps {
   project_id: "recipe_engine"
   url: "https://chromium.googlesource.com/external/github.com/luci/recipes-py.git"
   branch: "master"
-  revision: "28c10d465e3161ec3b862b525c5351ffe9343399"
+  revision: "4e4e32822f4b0aab38308d0d5c7b6561268702ed"
 }