adding serverstate enum type

src/server/ua_server.c

@@ -581,6 +581,7 @@ UA_Server * UA_Server_new(void) {
     addDataTypeNode(server, "DataValue", UA_NS0ID_DATAVALUE, UA_NS0ID_BASEDATATYPE);
     addDataTypeNode(server, "DiagnosticInfo", UA_NS0ID_DIAGNOSTICINFO, UA_NS0ID_BASEDATATYPE);
     addDataTypeNode(server, "Enumeration", UA_NS0ID_ENUMERATION, UA_NS0ID_BASEDATATYPE);
+    addDataTypeNode(server, "ServerState", UA_NS0ID_SERVERSTATE, UA_NS0ID_ENUMERATION);
 
     return server;
 }