Description of problem:
If user tries to create a repo w/o providing a name for said repo, an error is returned that is confusing to the user

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

Katello Version: 0.1.84-1.git.0.02da736.fc15

How reproducible:


Steps to Reproduce:
1. Create a new custom Provider (if necessary)
2. Create a new Product in this Provider, "Google"
3. Attempt to create a new repo within the "Google" provider. Do /not/ enter a name for this repo; for the URL, enter "http://dl.google.com/linux/chrome/rpm/stable/x86_64"
4. submit
  
Actual results:
Error message - 
Pulp::Repository: 401 Unauthorized "Invalid OAuth Credentials" (GET /pulp/api/repositories/?groupid=env%3A1&name=)

Expected results:
Something more user friendly and/or correct?

Additional info:
If user enters valid string for name and an URL, creation seems to work