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/9ba3130bd03e4dbaab1fd00a00f69b5237712d72 Don't coerce None to 0 when handling StepTestData in placeholder_step_data. (jbudorick@chromium.org)

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

Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Review-Url: https://codereview.chromium.org/2701803002

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: "e8470584a8a0a7a00541b1ab57e48f2793795743"
+  revision: "9ba3130bd03e4dbaab1fd00a00f69b5237712d72"
 }