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/4278a31afc8618c43ee029b85eba8f5aa3491dc7 Revert of Set proper result (purple/red) for "Uncaught Exception" and "Failure reason" steps (patchset #1 id:1 of https://codereview.chromium.org/2142833002/ ) (martiniss@chromium.org)

R=iannucci@chromium.org,estaab@chromium.org,martiniss@chromium.org,phajdan.jr@chromium.org
BUG=none

TBR=martiniss@chromium.org,phajdan.jr@chromium.org

Review-Url: https://codereview.chromium.org/2170553003

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: "e1a78d4ffd60b5bb4ae5a15a32f587a1a1f20e95"
+  revision: "4278a31afc8618c43ee029b85eba8f5aa3491dc7"
 }