Compilation fails with gcc 14+

[BtbN]

15.95 /50-libzmq/src/ip.cpp: In function 'int zmq::make_fdpair(fd_t*, fd_t*)':
15.95 /50-libzmq/src/ip.cpp:678:1: error: jump to label 'try_tcpip'
15.95   678 | try_tcpip:
15.95       | ^~~~~~~~~
15.95 /50-libzmq/src/ip.cpp:568:14: note:   from here
15.95   568 |         goto try_tcpip;
15.95       |              ^~~~~~~~~
15.95 /50-libzmq/src/ip.cpp:572:18: note:   crosses initialization of 'const SOCKET listener'
15.95   572 |     const SOCKET listener = open_socket (AF_UNIX, SOCK_STREAM, 0);
15.95       |      

This is an issue since #4734 was merged.
The variable needs to be zero-initialized before the goto at the very least.