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-client.cpp b/src/netconf-client.cpp
index 9f6908b..2869a1f 100644
--- a/src/netconf-client.cpp
+++ b/src/netconf-client.cpp
@@ -13,8 +13,8 @@
 #include <nc_client.h>
 }
 #include <sstream>
-#include "netconf-client.h"
-#include "UniqueResource.h"
+#include "netconf-client.hpp"
+#include "UniqueResource.hpp"
 
 namespace libnetconf {