fix include names

cppcheck isn't smart enough to recognize these are c++ headers, not c
headers.  Considering we're already inconsistent about our naming, it's
easier to just be consistent, and move the last few files to use .hpp
instead of .h.

Tested:
Code builds, no changes.

Signed-off-by: Ed Tanous <ed@tanous.net>
Change-Id: Ic348d695f8527fa4a0ded53f433e1558c319db40
diff --git a/redfish-core/include/node.hpp b/redfish-core/include/node.hpp
index 9863794..47c5cc6 100644
--- a/redfish-core/include/node.hpp
+++ b/redfish-core/include/node.hpp
@@ -15,9 +15,8 @@
 */
 #pragma once
 
-#include "http_request.h"
-#include "http_response.h"
-
+#include "http_request.hpp"
+#include "http_response.hpp"
 #include "privileges.hpp"
 
 #include <error_messages.hpp>