Update git submodules

* Update networking-generic-switch from branch 'master'
  to c6c10a12a83c894eb9c6a26658a010d37432afe7
  - CI: Fix Multinode ssh key/hostname for unit tests
    
    In multinode, the devstack plugin for networking-generic-switch can't
    really work as intended. But, the authorized keys is copied on all
    nodes, and zuul puts a consistent key in place, so it doesn't
    really need to do what it is doing, but we need to use the stack
    user's pre-existing keys to access the remote host.
    
    This will allow Ironic's multinode grenade job to work without
    errors about accessing the key file, which is a red herring for
    when the connection fails.
    
    Additionally, the underlying ngs code is suseptible to a race on
    configuration loading as configuration is loaded separately.
    
    We can't really force it to load the option. We also can't
    explicitly add it, so the best thing to do is to wrap it and
    rely upon a mock to facilitate the unit test.
    
    Change-Id: Ia8550c124f2ef1cce620a4fb28c35700d34aa027

networking-generic-switch

@@ -1 +1 @@
-Subproject commit 9f7d951496c34ce659a18ef3665d0c9dfe92bb66
+Subproject commit c6c10a12a83c894eb9c6a26658a010d37432afe7