remove provider form validation of imagefactory configs

[dajohnso]

Now that tim is in place, these values are passed directly to imagefactory instead of through the use of imagefactory config files so this check is no longer necessary afaik.

[dajohnso]

Ah, but they are still used by the conductor UI and not imagefactory. This probably needs to move to the database and its values configurable through the web ui which has been a pain point from the get go (including the management of the export domain nfs mount).