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
Merge "Big Switch: Switch to TLSv1 in server manager"