Update git submodules

* Update docs/submodules/integration.git from branch 'master'
  to 688355bf09c08f3a54362efe36eb7da0f3f09ca2
  - Fix missing images in staging manifest
    
    In order to unblock other teams, revert missing images in the
    staging manifest to their respective casablanca release
    versions.
    
    Change-Id: I37fa7791649d184bda3fac3178944e8c1e53d798
    Issue-ID: SDC-2114
    Issue-ID: MULTICLOUD-475
    Signed-off-by: Gary Wu <gary.i.wu@huawei.com>
    
1 file changed