update submodule to v.3.1.2

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

diff --git a/upstream b/upstream
index e17ac2503ccd41256aa4be078bb81e520a5b1c7f..650a3f15cfa8166a8d0763042b4acd39b12afde2 160000 (submodule)
--- a/upstream
+++ b/upstream
@@ -1 +1 @@
-Subproject commit e17ac2503ccd41256aa4be078bb81e520a5b1c7f
+Subproject commit 650a3f15cfa8166a8d0763042b4acd39b12afde2