Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 503d659ff3285bc1d07c563441c63c487f4f12e3
  - Merge "ModelInstanceName is required in SNIROHomingv2 to"
  - ModelInstanceName is required in SNIROHomingv2 to

    ModelInstanceName is required in SNIROHomingv2 to build placement
    demand. The source service does not have a modelInstanceName attribute,
    we need to set it to the service proxy modelInstanceName.

    Issue-ID: SO-2188
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@att.com>
    Change-Id: I85c0940b17349c8dd5dc171954acf9f884ccff9f

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 6915f19..503d659 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 6915f19540ea78f44254a37c6e318ea5d0b0e4f6
+Subproject commit 503d659ff3285bc1d07c563441c63c487f4f12e3