Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "[docs] Use https links"
  - [docs] Use https links

    Change-Id: Ieca3791520ed8c67943c34fe3ca94337f0511792
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index c0de090..02a91b3 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit c0de0902fdb9c15033ae830b31bfcade8eb1c3ec
+Subproject commit 02a91b3f16f31052b0a6ef867ddc9a3d8e305c71