onbrisca dies with after getting/setting configurations via control port

tor doesn't seem to have a limit on the number of queries that can be done in a given time to the control port, so maybe stem has it.

@meskio: was the error SocketClosed? Looking at the possible errors using stem's set_conf and get_conf (https://gitlab.torproject.org/tpo/network-health/stem/-/blob/master/stem/control.py#L2204), it isn't one of them, but maybe is inherited or it raised somewhere else.

I think a way to solve this could be incrementing sleep time between queries.