update to lxc-4.0.12

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

diff --git a/lxc b/lxc
index 48e079bf318982ae7d5684feeb7358870fa71c10..7e37cc96bb94175a8e351025d26cc35dc2d10543 160000 (submodule)
--- a/lxc
+++ b/lxc
@@ -1 +1 @@
-Subproject commit 48e079bf318982ae7d5684feeb7358870fa71c10
+Subproject commit 7e37cc96bb94175a8e351025d26cc35dc2d10543