Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "make website accessible via testresults.opnfv.org/test"
  - make website accessible via testresults.opnfv.org/test

    Currently, testapi website can not be fully accessed through
    testresults.opnfv.org/test, due to http://testresults.opnfv.org/test is
    not a root url. In this patch leverage relative path to make it accessible

    Change-Id: I56983d2221791d8a060039ec829278d31ecb5048
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 78ef942..9c4fbf3 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 78ef9426c9f8dd97e4ea886b08eea593264aec9b
+Subproject commit 9c4fbf3c75d3b36ad99bef7469c3df91f7637b69