Bump vpython pin 03693197fe -> b6cdec8586.

It is identical to the previous version (deployed in CL 1152103), except it has
one bug fixed (https://chromium-review.googlesource.com/1152364).

The bug shouldn't have any affect on vpython usage here. Updating it just to
make vpython version be in sync with all other places.

R=dpranke@chromium.org
TBR=bsheedy@chromium.org
BUG=821194

Change-Id: Iea7f380b4de2d01b649ce859ebf9bc222a3dd6da
Reviewed-on: https://chromium-review.googlesource.com/1153586Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578826}

chrome/test/vr/auto_bisect.py

@@ -359,10 +359,10 @@ def RunTestOnSwarming(args, unknown_args, output_dir):
     '${platform}:git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c',
 
     '.swarming_module:infra/tools/luci/vpython-native/'
-    '${platform}:git_revision:03693197fef4b7d6f2d717f99e9e616bb4f4d8a8',
+    '${platform}:git_revision:b6cdec8586c9f8d3d728b1bc0bd4331330ba66fc',
 
     '.swarming_module:infra/tools/luci/vpython/'
-    '${platform}:git_revision:03693197fef4b7d6f2d717f99e9e616bb4f4d8a8',
+    '${platform}:git_revision:b6cdec8586c9f8d3d728b1bc0bd4331330ba66fc',
   ]
   for package in cipd_packages:
     swarming_args.extend(['--cipd-package', package])

tools/mb/mb.py

@@ -385,9 +385,9 @@ class MetaBuildWrapper(object):
       ('infra/tools/luci/logdog/butler/${platform}',
        'git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c'),
       ('infra/tools/luci/vpython-native/${platform}',
-       'git_revision:03693197fef4b7d6f2d717f99e9e616bb4f4d8a8'),
+       'git_revision:b6cdec8586c9f8d3d728b1bc0bd4331330ba66fc'),
       ('infra/tools/luci/vpython/${platform}',
-       'git_revision:03693197fef4b7d6f2d717f99e9e616bb4f4d8a8'),
+       'git_revision:b6cdec8586c9f8d3d728b1bc0bd4331330ba66fc'),
     ]
     for pkg, vers in cipd_packages:
       cmd.append('--cipd-package=.swarming_module:%s:%s' % (pkg, vers))