Mitigate config disagreement issues
Mitigate config disagreement issues

Because the config file can change on us at any point, and each thread
carries around its own copy of it, it's possible that a thread can be
using an outdated version while in the middle of its work. This can
cause unexpected behavior, like uploading an image to a provider when
it is currently being deleted (leaving an undeleted upload). Until we
can solve the deeper issue of config file syncing, we can reduce
probability of this delete/upload problem by adding a check for the
build status _just_ before an upload attempt, and by reloading our
config after we spent time trying to upload to a provider (which can
take quite a while).

Also removes a TODO that was TODONE.

Change-Id: Id066361792d356cf7f22b9157092e364a848c8e1

Tesora/tesora-nodepool,Tesora/tesora-nodepool