Fix schema delta 15 on postgres in the very unlikley event that anyone upgrades to 15...
Fix schema delta 15 on postgres in the very unlikley event that anyone upgrades to 15...

matrix-org/synapse,matrix-org/synapse,TribeMedia/synapse,matrix-org/synapse,TribeMedia/synapse,matrix-org/synapse,matrix-org/synapse,matrix-org/synapse,TribeMedia/synapse,TribeMedia/synapse,TribeMedia/synapse