Handle servers that don't support NMDA

Change-Id: I4880f3bbed7485df18d0b27097b6dfc5fef6ef98
Bug: https://tree.taiga.io/project/jktjkt-netconf-cli/issue/222
diff --git a/src/netconf_access.hpp b/src/netconf_access.hpp
index 734e5ae..43ca1e8 100644
--- a/src/netconf_access.hpp
+++ b/src/netconf_access.hpp
@@ -59,6 +59,10 @@
 
     void doEditFromDataNode(std::shared_ptr<libyang::Data_Node> dataNode);
 
+    void checkNMDA();
+
+    bool m_serverHasNMDA;
+
     std::unique_ptr<libnetconf::client::Session> m_session;
     std::shared_ptr<YangSchema> m_schema;
 };