Remove nova_proxy_admin_* from guestagent code

[Mat Lowery]

Per SlickNik, "Things seem to work even with bogus values for those configs in the guest-agent."

https://bugs.launchpad.net/trove/+bug/1336618 will remove nova_proxy_admin_* from trove-guestagent.conf.sample. This bug is to remove it from the code.

Please remove nova_proxy_admin_* references here:
* http://git.io/TRGKBQ (here a regular Trove context is available to use instead)
* http://git.io/4G8Zfg (this is a periodic task so no context is available; since the conductor isn't using the context today, it is proposed that an empty dict be substituted here)

[Dan Nguyen (daniel-a-nguyen)]

The initial guest agent upgrades implementation also includes the use of nova_proxy_admin.

https://review.openstack.org/#/c/85225/71/trove/guestagent/heartbeat.py

I left as is for now but we can come back and fix it along with everything else.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/124355

[Nikhil Manchanda (slicknik)]

Issue is not release critical to hold juno-rc1 for. Moving to kilo-1.

[Amrith Kumar (amrith)]

Updating importance to "Wishlist" (bugscrub, 2014-10-23)

[OpenStack Infra (hudson-openstack)]

Change abandoned by Nikhil Manchanda (<email address hidden>) on branch: master
Review: https://review.openstack.org/124355
Reason: This patch is being Abandoned as part of routine cleanup (older than a month). Please feel to restore if it is still active. Thanks!