Proper error message required while deleting Roles.

A Proper error message has to through while roles deletion, If there is any user associated with roles.

Steps to reproduce:

• Login to zanata as admin.

• Go to admin section.

• Click on Manage Roles.

• Create two roles role1 and role2.

• Create new user and assign him role1.

• Now try to delete both roles.

• Observe the role1 deletion.

Actual Result:

• Unexpected error.

Expected Result:

• abc user is associated with this, are you sure you wants to delete this role. please change the role of user or delete it.

Note:

• attached screen captured.

Logs :

• http://pastebin.test.redhat.com/485043