This is a reland of 9ee86e5a

Fix: s/Httplib2Error/HttpLib2Error

Original change's description:
> gerrit-util: Fix GCE check from behind proxy.
>
> Setting HTTP_PROXY or HTTPS_PROXY environment variables will cause git cl
> to fail.
>
> The behavior of an unreachable server behind proxy is different from a direct
> connection, it won't throw a httplib2.ServerNotFoundError error,
> so catch httplib2.Httplib2Error instead.
>
> Bug: 1050380
> Change-Id: I32e2220483de1fd6222c7fd6063039fb86277ef0
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2050947
> Reviewed-by: Anthony Polito <apolito@google.com>
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

Bug: 1050380
Change-Id: I9aec01088b0b1c408a1292106d0b21e6d8997040
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2066666Reviewed-by: Anthony Polito <apolito@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>