Return what we have when we encounter missing events when servicing backfill/gme (#1499)
Return what we have when we encounter missing events when servicing backfill/gme (#1499)

We expect to have missing events as we walk back in the DAG over federation
as we didn't always create the room. When checking if the server is allowed
to see those events, just give up and stop rather than fail the request.
matrix-org/dendrite,matrix-org/dendrite,matrix-org/dendrite,matrix-org/dendrite