Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Use http instead of https as a workaround for certificate error"
  - Use http instead of https as a workaround for certificate error

    Got an SSL error when loading content from https://artifacts.opnfv.org [1]
    HTTPS is not a must for this use case, so use http instead to solve this issue.

    [1] https://nbviewer.jupyter.org/urls/artifacts.opnfv.org/qtip/review/37731/compute-qpi-report/report.ipynb

    Change-Id: I8b09eb2d1da234c17843f2cb7504a3b1ded9017e
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>