Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - xci: scripts: start-new-vm.sh: Make DEFAULT_XCI_TEST stricter

    The DEFAULT_XCI_TEST value wasn't checked and it could actually contain
    anything leading to all sort of failures so we need to check it against
    well known values.

    Change-Id: Ib12c944adebfbcb3097b42af98d2bacefbd8374c
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index 6c9da78..262b2a6 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit 6c9da781da57420edf4f2a4f823c9d413ea1f516
+Subproject commit 262b2a6e16be8abe06edac377094bcbaa84da378