Fixing of confusing user names in fig 1.3

Replacement of figure 'cloud_dash_user_list' in user-admin-guide
in order to clarify users assignations.

Change-Id: Id6d20c0a5d101dfd94b304732b1a6a3018fb3391
Closes-bug: #1304700
Merge "Fixing of confusing user names in fig 1.3"