Update git submodules

* Update docs/submodules/msb/apigateway.git from branch 'master'
  to 719802fea6fc36c91a4d142314a8521193eba871
  - Migrate msb-apigateway docs
    
    Merging this will create
    https://onap-msb-apigateway.readthedocs.io
    This build will run in parallel
    to the current docs generation method
    until we are ready to cut over.
    
    Issue-ID: CIMAN-364
    Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
    Change-Id: I8a80ccef0c4c6947d67e4dea3533fbebda2acc3f
    
1 file changed