Corrige crash au démarrage si moreblocks chargé

mapgen.lua

@@ -75,7 +75,7 @@ local c_sand = minetest.get_content_id("default:sand")
 
 local c_cobble = minetest.get_content_id("default:cobble")
 local c_mossycobble = minetest.get_content_id("default:mossycobble")
-local c_stair_cobble = minetest.get_content_id("stairs:stair_cobble")
+local c_stair_cobble = minetest.registered_nodes["moreblocks:stair_cobble"] and minetest.get_content_id("moreblocks:stair_cobble") or minetest.get_content_id("stairs:stair_cobble")
 
 local c_lava_source = minetest.get_content_id("default:lava_source")
 local c_lava_flowing = minetest.get_content_id("default:lava_flowing")
@@ -222,4 +222,4 @@ function nether.find_nether_ground_y(target_x, target_z, start_y)
 	end
 
 	return start_y -- Fallback
-end
+end