Rename .h header files to .hpp

Majority of the project uses .hpp and .h shouldn't be used for C++
header files anyway.

Change-Id: I979ba2d243f8f5dbf45c37237ac4aaf9a733eba8
diff --git a/src/netconf_access.cpp b/src/netconf_access.cpp
index 9fb456d..fd8f2a8 100644
--- a/src/netconf_access.cpp
+++ b/src/netconf_access.cpp
@@ -8,7 +8,7 @@
 #include <libyang/Libyang.hpp>
 #include <libyang/Tree_Data.hpp>
 #include "libyang_utils.hpp"
-#include "netconf-client.h"
+#include "netconf-client.hpp"
 #include "netconf_access.hpp"
 #include "utils.hpp"
 #include "yang_schema.hpp"