Update git submodules

* Update docs/submodules/appc.git from branch 'master'
  to 6c2b81d1d39e734435cabd66518fff26bcd49aec
  - Test coverage in MessageAdapterImpl
    
    Added test cases for untested portions of code
    
    Issue-ID: APPC-1481
    Change-Id: Id61ec5c5824c3d9fecbfb83d47bfa0164ae96759
    Signed-off-by: Joss Armstrong <joss.armstrong@ericsson.com>
    
1 file changed