[sonic-utilities]: Update submodule (#488)

sihuihan88 · Shuotian Cheng · commit 263c1bf85281 · 2017-04-07T11:28:07.000-07:00
[portstat]: return N/A if no counter info exists (#29)
diff --git a/src/sonic-utilities b/src/sonic-utilities
@@ -1 +1 @@
-Subproject commit 52cff2aa4412d3da78f4bb7cfe3018d427fb5d01
+Subproject commit ea8ceba23f104f27453db77bcffaebcfe2f3376f
