Rebased "Fix iteration logic in _handle_message_calls_in_progress shutdown loop to handle concurrent modification #598" to fix revert #637
Rebased "Fix iteration logic in _handle_message_calls_in_progress shutdown loop to handle concurrent modification #598" to fix revert #637

oxarbitrage/bitshares-core,bitshares/bitshares-2,oxarbitrage/bitshares-core,bitshares/bitshares-2,oxarbitrage/bitshares-core,bitshares/bitshares-2,pmconrad/graphene,bitshares/bitshares-2,pmconrad/graphene,pmconrad/graphene,pmconrad/graphene,oxarbitrage/bitshares-core