set namespacearray type (fix #921)

src/server/ua_server.c

@@ -925,6 +925,7 @@ UA_Server * UA_Server_new(const UA_ServerConfig config) {
     namespaceArray->valueSource = UA_VALUESOURCE_DATASOURCE;
     namespaceArray->value.dataSource = (UA_DataSource) {.handle = server, .read = readNamespaces,
                                                         .write = NULL};
+    namespaceArray->dataType = UA_TYPES[UA_TYPES_STRING].typeId;
     namespaceArray->valueRank = 1;
     namespaceArray->minimumSamplingInterval = 1.0;
     addNodeInternalWithType(server, (UA_Node*)namespaceArray, UA_NODEID_NUMERIC(0, UA_NS0ID_SERVER),