MINOR: tools: make str2sa_range() optionally return the fd

If a file descriptor was passed, we can optionally return it. This will
be useful for listening sockets which are both a pre-bound FD and a ready
socket.
diff --git a/src/hlua.c b/src/hlua.c
index b3b93e8..5589482 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -2534,7 +2534,7 @@
 	}
 
 	/* Parse ip address. */
-	addr = str2sa_range(ip, NULL, &low, &high, NULL, NULL, NULL, PA_O_PORT_OK | PA_O_STREAM);
+	addr = str2sa_range(ip, NULL, &low, &high, NULL, NULL, NULL, NULL, PA_O_PORT_OK | PA_O_STREAM);
 	if (!addr) {
 		xref_unlock(&socket->xref, peer);
 		WILL_LJMP(luaL_error(L, "connect: cannot parse destination address '%s'", ip));