Fix premature ranch_server:set_addr
Fix premature ranch_server:set_addr

With num_listen_sockets>1 and SO_REUSEPORT disabled, the startup of
ranch_acceptors_sup fails because extra sockets cannot be created.
Because ranch_server:set_addr is called right after the creation
of the first socket succeeded, ranch:get_port etc may still return
an ok tuple until it notices that the listener is in fact down.

ninenines/ranch,K2InformaticsGmbH/ranch