Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "xci: config: env-vars: Allow git urls overrides"
  - xci: config: env-vars: Allow git urls overrides

    It's useful to be able to pick alternative git repositories
    for the deployment. This facilitates testing in-flight features
    or simply save some bandwidth by keeping internal mirrors.

    Change-Id: I3eb2e48da1e91f6a52bb3ba14c22f0902c6cd777
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index df31d70..658d79e 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit df31d7021e0cda44fd0ccd057e4d63ec86152c76
+Subproject commit 658d79e3a47ff254aede2233208945bdb7793ee5