Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - xci: script: start-new-vm: Switch to using 'curl' instead of 'wget'

    curl supports the 'retry' argument to handle all sorts of connection
    problems so we can use it to retry if we encounter a broken connection.

    Change-Id: I3c8afd2be36ee36c5477f05495704bbbee5b9757
    Signed-off-by: Markos Chandras <mchandras@suse.de>