Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 8668df008ae252d0e43d23ef00c8e350bdb0900b
  - Merge "Fixed NPE in ResourceRequestBuilder"
  - Fixed NPE in ResourceRequestBuilder

    Fixed possible NullPointerException in ResourceRequestBuilder
    according to the Sonar analysis.

    Change-Id: Ide97a1a6439342ef55fc490916c945d194d4e518
    Issue-ID: SO-1498
    Signed-off-by: Robert Bogacki <r.bogacki@samsung.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index b5e31aa..8668df0 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit b5e31aaea92e3204d0257608f96eb1a182bcb37f
+Subproject commit 8668df008ae252d0e43d23ef00c8e350bdb0900b