OM3.0 - How to create only one My Room for new users

[henri]

How to create only one My Room for new users? As default it creates two 
different My Rooms:

My conference room (for 1-16 users)
Users 0 / 25
My webinar room (for 1-120 users)
Users 0 / 150

How to set it to create only one room?

Thanks!