added cocoa beans on_rightclick check for custom nodes

cocoa.lua

@@ -18,6 +18,13 @@ function place_cocoa(itemstack, placer, pointed_thing, plantname)
 		return
 	end
 
+	-- am I right-clicking on something that has a custom on_place set?
+	-- thanks to Krock for helping with this issue :)
+	local def = minetest.registered_nodes[under.name]
+	if def and def.on_rightclick then
+		return def.on_rightclick(pt.under, under, placer, itemstack)
+	end
+
 	-- check if pointing at jungletree
 	if under.name ~= "default:jungletree"
 	or minetest.get_node(pt.above).name ~= "air" then