One last-minute optimization broke the build without SSL support.
Move ssl_cert out of the #ifdef/#endif and it's OK.
char *interface; /* interface name or NULL */
int maxseg; /* for TCP, advertised MSS */
-#ifdef USE_OPENSSL
char *ssl_cert; /* ssl certificate */
+#ifdef USE_OPENSSL
struct {
SSL_CTX *ctx;
char *ciphers; /* cipher suite to use if non-null */
l_next = l->next;
unbind_listener(l);
delete_listener(l);
-#ifdef USE_OPENSSL
free(l->ssl_cert);
-#endif
free(l->name);
free(l->counters);
free(l);