Update git submodules

Update git submodules

* Update docs/submodules/sdnc/oam.git from branch 'master'
  to 74ad4c7e51bbfa01caa2e504779b47dd86861428
  - Fixes for async response to SO

    1) Wrong user name configured for SO interface
    2) Accept header needs to be set to 'text/plain'
    3) Content-Type needs to be explicitly set to 'application/json'
    4) Template is missing outer "input" tag
    5) Message needs to be in XML format, not JSON

    Change-Id: Icd06d12ff8576d2dd560ea452d0a14c3de643a00
    Issue-ID: SDNC-927
    Signed-off-by: Timoney, Dan (dt5972) <dtimoney@att.com>