Revert "bot_update: Set user.{name,email} when applying patch refs."

This reverts commit e86fe982.

Reason for revert: Probably causing outages on win7_chromium_rel_ng.

Original change's description:
> bot_update: Set user.{name,email} when applying patch refs.
> 
> git rebase complains when user name/email has not been configured, as was
> the case for the Chromium trybot.
> 
> Bug: 643346
> Change-Id: Iab7dac0a98608e09b63a53d5bacb98925701fbfd
> Reviewed-on: https://chromium-review.googlesource.com/1031524
> Reviewed-by: Aaron Gable <agable@chromium.org>
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

TBR=agable@chromium.org,ehmaldonado@chromium.org

Change-Id: Ic57398323476fccef34f766270d760c3975630a6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 643346
Reviewed-on: https://chromium-review.googlesource.com/1036308Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>

recipes/recipe_modules/bot_update/resources/bot_update.py

@@ -339,11 +339,6 @@ def gclient_sync(
   fd, gclient_output_file = tempfile.mkstemp(suffix='.json')
   os.close(fd)
 
-  # Some bots don't have git user name/email configured, which causes problems
-  # when rebasing.
-  git('config', 'user.name', 'chrome-bot')
-  git('config', 'user.email', 'chrome-bot@chromium.org')
-
   args = ['sync', '--verbose', '--reset', '--force',
          '--ignore_locks', '--output-json', gclient_output_file,
          '--nohooks', '--noprehooks', '--delete_unversioned_trees']

recipes/trigger_recipe_roller.txt

-No-op file. Edit this to kick recipes.
+No-op file. Edit this to kick recipes. (Did they do something wrong?)
 
 This is a beginning of a story in this silly file.
 Once upon a time, a budding web browser dev team needed a CI system.