Fixing json/protobuf confusion

peer/cwtch_peer.go

@@ -112,7 +112,7 @@ func (cp *cwtchPeer) ImportGroup(exportedInvite string) (groupID string, err err
 			cpp := &protocol.CwtchPeerPacket{}
 			err = proto.Unmarshal(data, cpp)
 			if err == nil {
-				jsobj, err := json.Marshal(cpp.GetGroupChatInvite())
+				jsobj, err := proto.Marshal(cpp.GetGroupChatInvite())
 				if err == nil {
 					cp.eventBus.Publish(event.NewEvent(event.NewGroupInvite, map[event.Field]string{
 						event.GroupInvite: string(jsobj),