Correct sample output of keystone user-role-list

The sample output of keystone user-role-list should keep the user-id
as same as previous output of keystone user-list, otherwise it will
be a bit confused for readers.

Change-Id: Icc5cc5a84ecfc279f3e00604f76601b3d995bed6
Closes-Bug: #1308501
Merge "Correct sample output of keystone user-role-list"