buildroot upgrade

jkt: Also, refactor that custom Unix group handling in buildroot to make
it unconditional. Fewer options, less work.

jkt: Also rebase systemd patch (now at lldp-json-250.4)

Change-Id: Icd8c22b8a2e6e9d0e3346a103bcfbcd78aecabac
Co-authored-by: Jan Kundrát <jan.kundrat@cesnet.cz>
diff --git a/board/czechlight/common/patches/systemd/0008-networkctl-allow-format-LLDP-capabilities-string-wit.patch b/board/czechlight/common/patches/systemd/0008-networkctl-allow-format-LLDP-capabilities-string-wit.patch
index 6b2c299..8e89013 100644
--- a/board/czechlight/common/patches/systemd/0008-networkctl-allow-format-LLDP-capabilities-string-wit.patch
+++ b/board/czechlight/common/patches/systemd/0008-networkctl-allow-format-LLDP-capabilities-string-wit.patch
@@ -1,4 +1,4 @@
-From b6b2ad094aba092aadda307c4d786a541d878211 Mon Sep 17 00:00:00 2001
+From de6ad887e413ee3e66e368f707e08ea84aa72a91 Mon Sep 17 00:00:00 2001
 From: Tomas Pecka <peckato1@users.noreply.github.com>
 Date: Wed, 15 Sep 2021 14:30:19 +0200
 Subject: [PATCH 8/9] networkctl: allow format LLDP capabilities string without
@@ -54,5 +54,5 @@
                  r = table_add_many(udata->table,
                                  TABLE_STRING, udata->link_name,
 -- 
-2.34.1
+2.35.1