Update git submodules

Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 2df391a041a85a0187a5eaad082d3a8f2fbaeaec
  - Merge "Handle when model cust uuid is null from sdnc"
  - Handle when model cust uuid is null from sdnc

    Modify wording on null uuid exception and test for it
    Expand null handling to vfmc and cvnfc find in lists
    Modify to chain the filter of nulls then to match.
    Change to ExpectedException in junit; filter nulls.
    Handle better when model cust. uuid is null from sdnc

    Change-Id: I1f1edffa1db84509bd649803660a55510868b6eb
    Issue-ID: SO-1989
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@us.att.com>