The actual original line of "When I die I want to be buried" is "Si je meurs..." not "Quand...". We usually don't have "When + indicative present tense" in the subordinate clause when the main clause is about something in the future. I've just checked on the internet and the only sites that give the lyrics as "Quand je meurs" (4 or 5) are not French. Well, I do admit that "Si" (If) doesn't translate the reality of life on earth as the only thing we can be sure about it's that we'll all die, so it's not about "if" but "when" but the song tells otherwise!