Update git submodules

Update git submodules

* Update docs/submodules/multicloud/k8s.git from branch 'master'
  to 845cdd2aa5d790e57b0b2999180df4abc6724bf1
  - Merge "Fix istio test scenario endpoint API validation"
  - Fix istio test scenario endpoint API validation

    Current query issued at the end of testcase to
    istio service API didn't validate the case, when
    http server responded with 5XX http code. By
    reusing common wrapper for cURL, this is now
    handled properly.

    Issue-ID: MULTICLOUD-686

    Signed-off-by: Konrad Bańka <k.banka@samsung.com>
    Change-Id: Ifb73494c9a6d98143edccaad095b2de5d456ef4f