Port to libyang-cpp and sysrepo-cpp API change to std::string

Change-Id: I2e922014ec0d280cccafc1fd5aa4ef6a575b1c9d
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/dependencies/+/5564
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/netconf-cli/+/5570
diff --git a/tests/sysrepo_system-ietfinterfaces.cpp b/tests/sysrepo_system-ietfinterfaces.cpp
index e20503e..2a54676 100644
--- a/tests/sysrepo_system-ietfinterfaces.cpp
+++ b/tests/sysrepo_system-ietfinterfaces.cpp
@@ -89,8 +89,8 @@
                                              {"osc", "iana-if-type:ethernetCsmacd"},
                                              {"oscW", "iana-if-type:ethernetCsmacd"},
                                              {"oscE", "iana-if-type:ethernetCsmacd"}}) {
-                client.setItem(("/ietf-interfaces:interfaces/interface[name='"s + name + "']/type").c_str(), type);
-                client.setItem(("/ietf-interfaces:interfaces/interface[name='"s + name + "']/enabled").c_str(), "false");
+                client.setItem("/ietf-interfaces:interfaces/interface[name='"s + name + "']/type", type);
+                client.setItem("/ietf-interfaces:interfaces/interface[name='"s + name + "']/enabled", "false");
             }
             client.applyChanges();
         }