Replaced MHD_RESPMEM_PERSISTENT usage in examples and code

New functions do not produce compiler warnings.

src/testcurl/https/test_https_session_info.c

@@ -84,9 +84,8 @@ query_session_ahc (void *cls, struct MHD_Connection *connection,
     }
   }
 
-  response = MHD_create_response_from_buffer (strlen (EMPTY_PAGE),
-                                              (void *) EMPTY_PAGE,
-                                              MHD_RESPMEM_PERSISTENT);
+  response = MHD_create_response_from_buffer_static (strlen (EMPTY_PAGE),
+                                                     EMPTY_PAGE);
   ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
   MHD_destroy_response (response);
   return ret;