Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Rename Functest creds

    It follows the change "Rename a common credential file for OS and
    K8S" which stops forcing OpenStack creds.

    [1] https://gerrit.opnfv.org/gerrit/#/c/51283/

    Change-Id: Ic83a2e696c9ea8821e29e6b3f4e69db25c528a0d
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index 1d77569..23e3c26 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit 1d775691155069aa730e671a285e6f25ce37cef1
+Subproject commit 23e3c26a3246a4a933710b7bb1845a077b015171