[aggregate] Missing error handling

[ln5]

Running bwscan --launch-tor aggregate:

2018-02-08T11:38:16+0100 [INFO]: Spawning a new Tor instance.
2018-02-08T11:38:16+0100 [INFO]: NoOpProtocolFactory starting on 43457
2018-02-08T11:38:16+0100 [INFO]: Aggregating data from past 1 scans.
2018-02-08T11:38:16+0100 [INFO]: (TCP Port 43457 Closed)
2018-02-08T11:38:16+0100 [INFO]: Spawning tor process with DataDirectory /tmp/tortmpGlQ8n4
2018-02-08T11:39:30+0100 [INFO]: Loading JSON measurement files
2018-02-08T11:39:30+0100 [INFO]: Loaded 85 successful measurements and 37 failures.
2018-02-08T11:39:30+0100 [INFO]: Processing the loaded bandwidth measurements
Unexpected error

Traceback (most recent call last):
Failure: txtorcon.torcontrolprotocol.TorProtocolError: 552 Unrecognized key "ns/id/D33D98BA997A883CA0973BEF5BA85B422E997881"
2018-02-08T11:39:30+0100 [CRITICAL]: Unexpected error

Traceback (most recent call last):
Failure: txtorcon.torcontrolprotocol.TorProtocolError: 552 Unrecognized key "ns/id/D33D98BA997A883CA0973BEF5BA85B422E997881"
2018-02-08T11:39:30+0100 [INFO]: Main loop terminated.

I would guess this is due to and unhandled failure in a get_info_raw() request initiated by write_aggregate_data() but I don't have any idea of where to add error handling code for this.

        routerstatus_info = yield tor.protocol.get_info_raw('ns/id/' + relay_fp.lstrip("$"))