openbmc-sfw: Intermittently unable to find Progress field in response

[geissonator]

This property goes away when the code update completes. Theory is that we're catching a race condition where the update is done and property is gone but we miss the "Active". Should just retry.

$ ./openbmc-sfw -I --server w37.aus.stglabs.ibm.com update_auto /scratch/arj/op-build/output/images/witherspoon.pnor.squashfs.tar 
Activation Progress: 10%
Activation Progress: 10%
Traceback (most recent call last):
  File "./openbmc-sfw", line 254, in <module>
    args.func(args)
  File "./openbmc-sfw", line 185, in do_update_auto
    s.update_auto(args.image, args.reboot)
  File "./openbmc-sfw", line 95, in update_auto
    self.__wait_for_activation(image_id)
  File "./openbmc-sfw", line 150, in __wait_for_activation
    print 'Activation Progress: ' + str(image['Progress']) + '%'
KeyError: 'Progress'

FYI @charleshofer @anoo1 @amboar