Roll vpython.

This picks up luci-go @ 0b4a49dd79cb1e7ef737a7ebea37c63c50f21ced
which adds awareness of the "linux-aarch64" platform/architecture
to vpython.

TBR=dnj@chromium.org, vadimsh@chromium.org

Bug: 764710
Change-Id: Ib2098c89c64d042879ddb8d281513616d49087ef
Reviewed-on: https://chromium-review.googlesource.com/665305Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>

cipd_manifest.txt

@@ -3,7 +3,7 @@
 # found in the LICENSE file.
 
 # vpython.
-infra/tools/luci/vpython/${platform}  git_revision:0aa5e4d06ec4d3b90980fcb0d0b7c34a5e65b9e1
+infra/tools/luci/vpython/${platform}  git_revision:fb827c61d6f945aaa31f200cacf2ccb7df91aac3
 
 # LUCI editor
 infra/tools/luci/led/${platform}  git_revision:0aa5e4d06ec4d3b90980fcb0d0b7c34a5e65b9e1