Description of problem:
I am not able to choose readonly DB user's username. 

Version-Release number of selected component (if applicable):
rhevm-dwh.noarch 0:3.3.0-28.el6ev

How reproducible:


Steps to Reproduce:
1. rhevm-dwh-setup
2. yes, yes
3. whatever

Actual results:
This utility can configure a read only user for DB access. Would you like to do so? (yes|no): yes
Error: user name cannot be empty
Provide a username for read-only user : readonlyuser
"readonlyuser" role already exists in the DB and cannot be used for creating read only user.
Provide a username for read-only user : readonly
"readonly" role already exists in the DB and cannot be used for creating read only user.
Provide a username for read-only user : foobar
"foobar" role already exists in the DB and cannot be used for creating read only user.
Provide a username for read-only user : 
\Not a valid answer. Try again
Provide a username for read-only user : 

Expected results:


Additional info: