Explicitly use HTTPS to download the CCT binary

TBR=mattm@chromium.org
BUG=598752

Review URL: https://codereview.chromium.org/1908613002

Cr-Commit-Position: refs/heads/master@{#388555}
(cherry picked from commit ff7b8097333f0abd117606334dc925b09a2b247f)

Review URL: https://codereview.chromium.org/1919043002 .

Cr-Commit-Position: refs/branch-heads/2704@{#229}
Cr-Branched-From: 6e53600def8f60d8c632fadc70d7c1939ccea347-refs/heads/master@{#386251}
1 file changed