Discovered during dialog parsing.
Richard dialog node 51 makes reference to nodes 30 and 31. Nodes 30|31 do not
exist anywhere in the dialog file.

[code]
line 129
{
	id = "node51",
	text = _"Yes, please teach me.",
	code = function()
		if (Tux:train_program(300....
			Npc:says(_"Good....
			Npc:says(_"Once ...
			Npc:says(_"Now I ...
			hide("node31") show("node30")
		else
			if (Tux:get_gold() < 300 ) then
				next("node52")
			else
				next("node41")
			end
		end
	end,
},
[/code]

Fixed with submission of RR-2132.

Fix pushed as 8e473eec20791bbf6ce32c868cd4fe951d51c39c , thanks!
Please don't close a ticket before the actual fix has been pushed to the repo to
avoid chaos. :)