Can't see who updated a group

[vvug]

After a group is modified ("updated" in Signal's jargon, see #6193) the other users just see a "Group updated." message if one user was added, or "Group name is now 'newname'.". These messages should show who made the change, for example:

"Masha added Alice the group."
"Masha refreshed the user list." <- Group update received, but with no new members
"Masha renamed to group to 'newname'."

[rainerzufall]

There is an open PR which addresses improving the group update behaviour : #5416

[vvug]

Fixed by 3506f2d.