Updated git submodules

Project: sdc master ff31b1eea7a5aec585fbbdf5004d2c1d93f4437e

fix sonar complaints NullPointerException in SDC

bugs from https://sonar.onap.org/project/issues?id=
org.openecomp.sdc%3Asdc-main%3A1.2.0-SNAPSHOT&open=
AWIFjPUXRGy6eclHC_Q6&resolved=false&types=BUG
and https://sonar.onap.org/project/issues?id=
org.openecomp.sdc%3Asdc-main%3A1.2.0-SNAPSHOT&open=
AWIFjPUXRGy6eclHC_Q5&resolved=false&types=BUG

Change-Id: I88225e4da197bed62d588026564bd688a9627c8a
Issue-ID: SDC-1146
Signed-off-by: lding7 <liang.ding@intel.com>

diff --git a/docs/submodules/sdc.git b/docs/submodules/sdc.git
index 65029c3..ff31b1e 160000 (submodule)
--- a/docs/submodules/sdc.git
+++ b/docs/submodules/sdc.git
@@ -1 +1 @@
-Subproject commit 65029c3dfc0f876284489009a01252e1088eac03
+Subproject commit ff31b1eea7a5aec585fbbdf5004d2c1d93f4437e