Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Reporting docker deployment improvement"
  - Reporting docker deployment improvement

    In the patch, I make build pages(landing page ...),
    when docker build, when run a container, we can set
    the api url(default:testresults.opnfv.org/reporting2) by -e;

    For example:
    1. In testresults.opnfv.org:
    docker run -itd -p 8888:8000 -p 80:80 opnfv/reporting:tag
    visit: http://testresults.opnfv.org/reporting2/reporting/index.html

    2. Personal use:
    docker run -itd -p 8888:8000 -p 80:80 -e SERVER_URL=192.168.131.2:8888 opnfv/reporting:tag
    visit: http://192.168.131.2:8888/reporting/index.html

    Change-Id: Ib838c12e785151acf9852f25eab254aedc520a1d
    Signed-off-by: chenjiankun <chenjiankun1@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index c7c0184..6b8f885 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit c7c018465d458a5bd98cd630620c052db784f615
+Subproject commit 6b8f885df235649608e70a9a4337e8493705a32a