Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to d9160c65acd59d9e844b1ca72e6da7c6ee30f1fc
  - Merge "switch to docker-maven-plugin because that's all"
  - switch to docker-maven-plugin because that's all

    switch to docker-maven-plugin because that's all we need

    Issue-ID: SO-2933
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@att.com>
    Change-Id: I65783d3a7c172f4ce7fc39d64a3987eeae58feed

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 40d0e02..d9160c6 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 40d0e02c799115c2f070e93d35a9384264b332e2
+Subproject commit d9160c65acd59d9e844b1ca72e6da7c6ee30f1fc