Add test to verify behaviour when a participant with no devices is removed
On the server side, if a participant without any registered devices is explicitely removed by an admin, then he/she is deleted immediately from the database As soon as his/her device registers, the SUBSCRIBE to the chatroom will be replied with 603. If the client sends a list of chatrooms, then the server will omit all updates regarding the chatroom the participant has been removed from
Edited by Andrea Gianarda