This change made in 7.8 broke on some vmware servers, and also causes
some freezes during concurrent transfers on Linux (just a few tens of
connections are sufficient to block sshd over a gigabit link). Ubuntu
reverted it to switch back to the original defaults, let's do the same.

--- ./readconf.c.bad	2023-03-15 22:28:19.000000000 +0100
+++ ./readconf.c	2023-04-10 23:03:32.926805464 +0200
@@ -2606,9 +2606,9 @@
 	if (options->visual_host_key == -1)
 		options->visual_host_key = 0;
 	if (options->ip_qos_interactive == -1)
-		options->ip_qos_interactive = IPTOS_DSCP_AF21;
+		options->ip_qos_interactive = IPTOS_LOWDELAY;
 	if (options->ip_qos_bulk == -1)
-		options->ip_qos_bulk = IPTOS_DSCP_CS1;
+		options->ip_qos_bulk = IPTOS_THROUGHPUT;
 	if (options->request_tty == -1)
 		options->request_tty = REQUEST_TTY_AUTO;
 	if (options->session_type == -1)
--- ./servconf.c.bad	2023-03-15 22:28:19.000000000 +0100
+++ ./servconf.c	2023-04-10 23:02:45.308844102 +0200
@@ -427,9 +427,9 @@
 	if (options->permit_tun == -1)
 		options->permit_tun = SSH_TUNMODE_NO;
 	if (options->ip_qos_interactive == -1)
-		options->ip_qos_interactive = IPTOS_DSCP_AF21;
+		options->ip_qos_interactive = IPTOS_LOWDELAY;
 	if (options->ip_qos_bulk == -1)
-		options->ip_qos_bulk = IPTOS_DSCP_CS1;
+		options->ip_qos_bulk = IPTOS_THROUGHPUT;
 	if (options->version_addendum == NULL)
 		options->version_addendum = xstrdup("");
 	if (options->fwd_opts.streamlocal_bind_mask == (mode_t)-1)