Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 81d98b8aeb793ace664a30283df03821bea1930a
  - Merge "Remove import,variable,shift constructor call"
  - Remove import,variable,shift constructor call
    
    Remove unused import,variable,shift constructor call MsoVnfPluginAdapterImpl class
    
    Issue-ID: SO-1490
    
    Change-Id: I1d722d7157ccbb9366dfe0ae60529c40615bb8e3
    Signed-off-by: Sindhuri.A <arcot.sindhuri@huawei.com>
    
diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 7fbb90d..81d98b8 160000
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 7fbb90dfacc3034432df073faa094a6f4747c210
+Subproject commit 81d98b8aeb793ace664a30283df03821bea1930a