[sonic-platform-common] Update submodule (#2346)

jleveque · web-flow · commit 15321e3be550 · 2018-12-04T17:47:06.000-08:00
diff --git a/src/sonic-platform-common b/src/sonic-platform-common
@@ -1 +1 @@
-Subproject commit 0d1622a3d06c92f03d13062553c27b087c1e8974
+Subproject commit d4bf78c9db4daf21497274a778748da4d8301866
