Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - [baremetal] Fix maas_subnets without maas_fabrics

    Change-Id: I603b39d46d3f2f2448b8f9746ad0745e416bbee7
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit 2c48915a1a77aa3ac0133155fd0cdadbf280493d)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index d42dfd1..abf9b9a 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit d42dfd19e88e280a8a5f531aab7ae06d4fd413ba
+Subproject commit abf9b9a8363e308daaaf297450222cf8c5397868