Bring back X-Auth-Token by default

It seems that requests are made to other places than API so this
token is still required there (Health check for example with OSTF).

Change-Id: I2f0e47a57b360abd04f2ca21fc013ccd34d84eec
Closes-Bug: #1379000
(cherry picked from commit 207580c58842166ef516b36e5917be251b7472ec)