Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - bash scripts: Fix remaining shellcheck warn/errs

    Fix/silence all shellcheck errors, except for scripts in
    <prototypes/sfc_tacker>.

    Change-Id: Idc317cdba0f69b78299f2d3665e72ffc19dd8af5
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 9131283..8b810c6 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 91312836e649c24d2d0268f1f5c8aa45fdd79a8d
+Subproject commit 8b810c6a4d80112a2d07cc5599984403d590579d