Fix windows build (#391)

Author: yinggeh

src/tritonserver_stub.cc

@@ -1075,6 +1075,26 @@ TRITONSERVER_MetricFamilyDelete()
 {
 }
 
+TRITONAPI_DECLSPEC void
+TRITONSERVER_GetMetricFamilyKind()
+{
+}
+
+TRITONAPI_DECLSPEC void
+TRITONSERVER_MetricArgsNew()
+{
+}
+
+TRITONAPI_DECLSPEC void
+TRITONSERVER_MetricArgsSetHistogram()
+{
+}
+
+TRITONAPI_DECLSPEC void
+TRITONSERVER_MetricArgsDelete()
+{
+}
+
 TRITONAPI_DECLSPEC void
 TRITONSERVER_MetricNew()
 {