Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "bugfix: testapi is killed because of oom_kill"
  - bugfix: testapi is killed because of oom_kill

    if page is not provided, return page 1 to avoid large memory consume,
    further more to kill testapi:

    Out of memory: Kill process 30842 (opnfv-testapi) score 519 or sacrifice child
    Killed process 30842 (opnfv-testapi) total-vm:4739716kB, anon-rss:3974612kB, file-rss:0kB

    JIRA: RELENG-291

    Change-Id: Id0e144c030aee390cc41cff8a48e3c997de4ad84
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index b6d1249..8151d9a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit b6d124999387d3a1b86ba046a89f6e96863a9b55
+Subproject commit 8151d9aacd51a5e8b9d68845fca6b15448210937