remove token from notifier middleware

oslo-incubator sync to address the security bug
in middleware (as below).

notifier middleware is capturing token and sending it to MQ. this
is not advisable so we should filter it out.

Change-Id: Ia1bfa1bd24989681db1d2f385defc12e69a01f8d
Closes-Bug: #1321080
(cherry picked from commit 0324965a0c2987e5cad6276f011682dec184205f)