Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to da123b489a80779f3162d9e007616c6a083414bc
  - Add notification test for e2eSlicing
    
    Issue-ID: SO-2758
    
    Signed-off-by: zm330 <zhangminyj@chinamobile.com>
    Change-Id: I4635d3b4ef911c8bd2269407a5aa8709027244bf
    
1 file changed