Update git submodules

* Update docs/submodules/dmaap/messagerouter/messageservice.git from branch 'master'
  to 8537f3c5ee8bf3897404dff5442c6a10f4d1420d
  - clean MR codebase
    
    Issue-ID: DMAAP-1199
    Change-Id: Ieff7939b02a8987b6101dd1c0ec886b474f1fa82
    Signed-off-by: sunil.unnava <sunil.unnava@att.com>
    
1 file changed