Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 3d55c357d5263c8b81e848b0c1efae777e3f7f9e
  - restoring the pnf dmaap client functionality to the proper working version

    Issue-ID: SO-2339
    Change-Id: I2a12517fd7b37d3260058be6c5c27865e207b861
    Signed-off-by: Lukasz Muszkieta <lukasz.muszkieta@nokia.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index f3aade5..3d55c35 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit f3aade51a88b6708233ba486bb578ad436909796
+Subproject commit 3d55c357d5263c8b81e848b0c1efae777e3f7f9e