[blinkpy] DEBUG: Temporarily turn stderr back on

Bug: 1050060
Change-Id: Ib326d6a0ec2b4497a581c379424c1b5ba0ccf21b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2043856
Commit-Queue: Robert Ma <robertma@chromium.org>
Commit-Queue: Luke Z <lpz@chromium.org>
Auto-Submit: Robert Ma <robertma@chromium.org>
Reviewed-by: Luke Z <lpz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739434}

third_party/blink/tools/blinkpy/common/net/git_cl.py

@@ -85,7 +85,7 @@ class GitCL(object):
         # Suppress the stderr of git-cl because git-cl will show a warning when
         # running on Swarming bots with local git cache.
         return self._host.executive.run_command(
-            command, cwd=self._cwd, return_stderr=False, ignore_stderr=True)
+            command, cwd=self._cwd, return_stderr=False, ignore_stderr=False)
 
     def trigger_try_jobs(self, builders, bucket=None):
         """Triggers try jobs on the given builders.