examples: calendar_cxx: comment out unused variables

I normally would simply remove them, but they belong to some more
commented out code below. We should either remove both or get this
fixed.

unsorted/elementary/calendar_cxx_example_04.cc

@@ -9,8 +9,10 @@ using efl::eo::instantiate;
 static void
 efl_main(void *data EINA_UNUSED, const Efl_Event *ev EINA_UNUSED)
 {
+#if 0
    struct tm selected_time;
    time_t current_time;
+#endif
 
    elm_policy_set(ELM_POLICY_QUIT, ELM_POLICY_QUIT_LAST_WINDOW_HIDDEN);