Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 15b9f3c6cbb69a243e4fd98add2cc2aebe83daf4
  - Merge "serviceinstanceid being overwritten by vnfid in"
  - serviceinstanceid being overwritten by vnfid in

    Added check for vnfReplace before setting serviceInstanceId
    Added test to make sure serviceInstanceId is not overwritten
    Removed unused action import from WorkflowAction
    Formatted WorkflowActionTest to fix build failure

    Issue-ID: SO-2553
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@att.com>
    Change-Id: I04cc668d4afbecd67b169f4e9d357ffc68cab02a

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 2ded41a..15b9f3c 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 2ded41a112f4a70b4488b5887ba366d159ea76a4
+Subproject commit 15b9f3c6cbb69a243e4fd98add2cc2aebe83daf4