Update git submodules

* Update docs/submodules/fuel from branch 'stable/fraser'
  - [patch] Rebase keyserver proxy support (3)

    Rebased on top of [1].

    [1] https://github.com/salt-formulas/salt-formula-linux/commit/9f30456

    Change-Id: Iad5aef674c47d622a94d1c21cae3f46fbb3c52d8
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit fd1f3fa1c8c83b2e5f8cacc6a6caf1a14e40b1a5)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 7e44402..c6de902 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 7e44402abfc0bb8e314109ef4746405755e43d42
+Subproject commit c6de9021d6b387e24363dcf4eb35692ef82d439f