core in order to keep the backward compatibility.
The SDK now stores the addresses of the conference without the gr
parameter as it will negatively affect the high availability capability
of a server and it will make it dependent on keeping the same gr all the
time. Therefore clients might be lead to call the conference without
specifying the gr parameter in the To field of the INVITE.
If a conference address was stored with the gr parameter, the core would
not be able to find it as it compares strings and not Address objects.