Big Switch: Switch to TLSv1 in server manager

Switch to TLSv1 for the connections to the backend
controllers. The default SSLv3 is no longer considered
secure.

TLSv1 was chosen over .1 or .2 because the .1 and .2 weren't
added until python 2.7.9 so TLSv1 is the only compatible option
for py26.

Closes-Bug: #1384487
Change-Id: I68bd72fc4d90a102003d9ce48c47a4a6a3dd6e03
(cherry picked from commit 62588957fbeccfb4f80eaa72bef2b86b6f08dcf8)