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/168be2068b30c07600603f1ce7fffe8f21348965 [doc/recipes.py] stop intercepting --help (iannucci@chromium.org)

TBR=iannucci@chromium.org

Change-Id: If3c76b68fd224eae3bf5c333ca80ef633a7554a1
Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Reviewed-on: https://chromium-review.googlesource.com/473791
Reviewed-by: <recipe-roller@chromium.org>
Commit-Queue: <recipe-roller@chromium.org>

infra/config/recipes.cfg

@@ -3,7 +3,7 @@
   "deps": {
     "recipe_engine": {
       "branch": "master",
-      "revision": "e47e63a157739d48e41f71a2d3827d1a38277359",
+      "revision": "168be2068b30c07600603f1ce7fffe8f21348965",
       "url": "https://chromium.googlesource.com/external/github.com/luci/recipes-py.git"
     }
   },

recipes/recipes.py

@@ -102,7 +102,7 @@ def find_engine_override(argv):
   any, or None if the user didn't override it."""
   PREFIX = 'recipe_engine='
 
-  p = argparse.ArgumentParser()
+  p = argparse.ArgumentParser(add_help=False)
   p.add_argument('-O', '--project-override', action='append')
   args, _ = p.parse_known_args(argv)
   for override in args.project_override or ():