smartlist_choose_node_by_bandwidth() does not consider bad exit
smartlist_choose_node_by_bandwidth() does not check for the bad exit flag, and can return badexited relays. The sister function smartlist_choose_node_by_bandwidth_weights correctly checks for the bad exit flag.
The good thing is that node_sl_choose_by_bandwidth() will only use the faulty function if the bandwidth weight system fails. This should not happen to the current network though. Hence, this does not seem to be a big issue.
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