Don't fiddle with results returned by event sources
Don't fiddle with results returned by event sources

Overwriting hashes returned by other methods is poor form.

Fixes: SYN-516

matrix-org/synapse,matrix-org/synapse,iot-factory/synapse,TribeMedia/synapse,matrix-org/synapse,matrix-org/synapse,iot-factory/synapse,matrix-org/synapse,iot-factory/synapse,TribeMedia/synapse,TribeMedia/synapse,iot-factory/synapse,matrix-org/synapse,TribeMedia/synapse,TribeMedia/synapse,iot-factory/synapse