remove unused variable

src/tcp_listener.cpp

@@ -53,7 +53,6 @@ zmq::tcp_listener_t::tcp_listener_t (io_thread_t *io_thread_,
       socket_base_t *socket_, const options_t &options_) :
     own_t (io_thread_, options_),
     io_object_t (io_thread_),
-    has_file (false),
     s (retired_fd),
     socket (socket_)
 {

src/tcp_listener.hpp

@@ -68,9 +68,6 @@ namespace zmq
         //  Address to listen on.
         tcp_address_t address;
 
-        //  True, if the undelying file for UNIX domain socket exists.
-        bool has_file;
-
         //  Underlying socket.
         fd_t s;