Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to ccc73d17e36b747cf9158c086adffe522240b5f4
  - Merge "removal of unused file imports. removal of unused file imports. Issue-ID: SO-1490"
  - removal of unused file imports.
    removal of unused file imports.
    Issue-ID: SO-1490

    Change-Id: I35c09f25f363c7da276beece4fff854f8f42a2f8
    Signed-off-by: Subhosree Pan <subhosree.pan1@huawei.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 748ba79..ccc73d1 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 748ba79228f388edc1a9028f82e82475fd771fc1
+Subproject commit ccc73d17e36b747cf9158c086adffe522240b5f4