update to kronosnet 1.26

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

diff --git a/upstream b/upstream
index 9ba801e46256ba942d0bbd1ca63ce32bbe70ab40..a40c3549012f3e418626dec02c8999ac0aa83d04 160000 (submodule)
--- a/upstream
+++ b/upstream
@@ -1 +1 @@
-Subproject commit 9ba801e46256ba942d0bbd1ca63ce32bbe70ab40
+Subproject commit a40c3549012f3e418626dec02c8999ac0aa83d04