Groups are assigned new IDs when the carrier is restarted

[peter-strauss]

In case one or multiple groups are created or joined, a group ID is assigned, however when the carrier is restarted and the list of groups is retrieved, the IDs of the groups are changed.

This issue affects the application layer such that other group attributes such as title cannot be assigned due to the missing ( or incorrectly replaced ) unique key values.

Automatically rejoining and sending messages to groups works correctly.