fix embarassing bug where in-progress messages get vaped when the previous one gets delivered
fix embarassing bug where in-progress messages get vaped when the previous one gets delivered

matrix-org/synapse,iot-factory/synapse,howethomas/synapse,howethomas/synapse,illicitonion/synapse,iot-factory/synapse,matrix-org/synapse,matrix-org/synapse,TribeMedia/synapse,howethomas/synapse,iot-factory/synapse,illicitonion/synapse,rzr/synapse,howethomas/synapse,illicitonion/synapse,rzr/synapse,TribeMedia/synapse,rzr/synapse,matrix-org/synapse,iot-factory/synapse,illicitonion/synapse,matrix-org/synapse,rzr/synapse,iot-factory/synapse,rzr/synapse,matrix-org/synapse,TribeMedia/synapse,TribeMedia/synapse,TribeMedia/synapse,howethomas/synapse,illicitonion/synapse