Update git submodules

* Update docs/submodules/releng from branch 'master'
  - fix dovetail branch issue

    error logs

    https://build.opnfv.org/ci/view/dovetail/job/dovetail-fuel-baremetal-proposed_tests-danube/43/console

    Change-Id: I0634041a0679fa7f3e6a4e6c627b3205a3b0372d
    Signed-off-by: MatthewLi <matthew.lijun@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index f0999be..6678526 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit f0999bee4dd3b410cd01a08ca28edc172aaf52bd
+Subproject commit 667852687522ba836878da05a2734a7399b74e2e