Description of problem:

When user hits the Upload button without having actually chosen a file, an error is thrown to the screen that probably should be caught and returned to the user in a friendly manner.

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1.  Content > Providers > Red Hat > Subscriptions
2.  Hit the Upload button prior to ever trying to provide an actual file.
3.  View results
  
Actual results:
Error message: 
Missing partial providers/subscriptions with {:formats=>[:js, "application/ecmascript", "application/x-ecmascript", "*/*"], :locale=>[:en, :en], :handlers=>[:builder, :haml, :rjs, :erb, :rhtml, :rxml]} in view paths "/usr/share/katello/app/views"

Expected results:
Caught error message.

Additional info: