Bump liberty, check the connection while searching

This just prevents immediate assertion failures.

README.adoc

@@ -33,6 +33,8 @@ You can get a package with the latest development version using Arch Linux's
 https://aur.archlinux.org/packages/nncmpp-git[AUR],
 or as a https://git.janouch.name/p/nixexprs[Nix derivation].
 
+Stable versions are present in: OpenBSD ports.
+
 Documentation
 -------------
 See the link:nncmpp.adoc[man page] for information about usage.

nncmpp.c

@@ -3785,6 +3785,8 @@ static void
 search_on_changed (void)
 {
 	struct mpd_client *c = &g.client;
+	if (c->state != MPD_CONNECTED)
+		return;
 
 	size_t len;
 	char *u8 = (char *) u32_to_u8 (g.editor.line, g.editor.len + 1, NULL, &len);