jamiaccount: fix multi-devices calls with cached connections

onConnectedOutgoingCall must be called after that every subCall is added. If
it's not the case, the new subcalls will not be added and will be removed.
So, every call created after onConnectedOutgoingCall will be immediately
deleted.

Change-Id: I0e6b394e9882bff552d3d5a35ebc3cdc07c49857
Gitlab: #209