[core] Fix for last commit: undefined flag with older libev headers so have to use makros

src/main/server.c

@@ -306,9 +306,11 @@ static gpointer server_worker_cb(gpointer data) {
 
 gboolean li_server_loop_init(liServer *srv) {
 	/* disable usage if signalfd for libev 3.8, it breaks signal handling. 3.9+ have it disabled by default */
-	if (EV_VERSION_MAJOR == 3 && EV_VERSION_MINOR == 8 && ev_version_major() == 3 && ev_version_minor() == 8) {
+#if EV_VERSION_MAJOR == 3 && EV_VERSION_MINOR == 8
+	if (ev_version_major() == 3 && ev_version_minor() == 8) {
 			srv->loop_flags |= EVFLAG_NOSIGFD;
 	}
+#endif
 
 	srv->loop = ev_default_loop(srv->loop_flags);