An external developer reported that gclient sync fails on Windows 8.1
unless TLS 1.2 is explicitly enabled. This allows that security protocol
and prints a more detailed error message on failures.

Change-Id: I07ab832d4f922264a1ee1890f9b71949a313a7ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2480605
Commit-Queue: Anthony Polito <apolito@google.com>
Reviewed-by: Anthony Polito <apolito@google.com>