conf, passt.1: Un-deprecate --host-lo-to-ns-lo

It was established behaviour, and it's now the third report about it:
users ask how to achieve the same functionality, and we don't have a
better answer yet.

The idea behind declaring it deprecated to start with, I guess, was
that we would eventually replace it by more flexible and generic
configuration options, which is still planned. But there's nothing
preventing us to alias this in the future to a particular
configuration.

So, stop scaring users off, and un-deprecate this.

Link: https://archives.passt.top/passt-dev/20240925102009.62b9a0ce@elisabeth/
Link: https://github.com/rootless-containers/rootlesskit/pull/482#issuecomment-2591855705
Link: https://github.com/moby/moby/issues/48838
Link: https://github.com/containers/podman/discussions/25243
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

conf.c

@@ -963,8 +963,7 @@ pasta_opts:
 		"  -U, --udp-ns SPEC	UDP port forwarding to init namespace\n"
 		"    SPEC is as described above\n"
 		"    default: auto\n"
-		"  --host-lo-to-ns-lo	DEPRECATED:\n"
-		"			Translate host-loopback forwards to\n"
+		"  --host-lo-to-ns-lo	Translate host-loopback forwards to\n"
 		"			namespace loopback\n"
 		"  --userns NSPATH 	Target user namespace to join\n"
 		"  --netns PATH|NAME	Target network namespace to join\n"

passt.1

@@ -622,7 +622,7 @@ Configure UDP port forwarding from target namespace to init namespace.
 Default is \fBauto\fR.
 
 .TP
-.BR \-\-host-lo-to-ns-lo " " (DEPRECATED)
+.BR \-\-host-lo-to-ns-lo
 If specified, connections forwarded with \fB\-t\fR and \fB\-u\fR from
 the host's loopback address will appear on the loopback address in the
 guest as well.  Without this option such forwarded packets will appear