Fix flickering of encrypted messages when sending using new store

src/timeline/TimelineModel.cpp

@@ -776,6 +776,7 @@ TimelineModel::sendEncryptedMessage(const std::string txn_id, nlohmann::json con
                         event.room_id          = room_id;
                         event.sender           = http::client()->user_id().to_string();
                         event.type             = mtx::events::EventType::RoomEncrypted;
+                        event.origin_server_ts = QDateTime::currentMSecsSinceEpoch();
 
                         emit this->addPendingMessageToStore(event);
                         return;
@@ -815,6 +816,7 @@ TimelineModel::sendEncryptedMessage(const std::string txn_id, nlohmann::json con
                                 event.room_id          = room_id;
                                 event.sender           = http::client()->user_id().to_string();
                                 event.type             = mtx::events::EventType::RoomEncrypted;
+                                event.origin_server_ts = QDateTime::currentMSecsSinceEpoch();
 
                                 emit this->addPendingMessageToStore(event);
                         } catch (const lmdb::error &e) {