Fix [modify_side]reset_maps|view

Addresses #5897

data/lua/wml/modify_side.lua

@@ -61,13 +61,13 @@ function wesnoth.wml_actions.modify_side(cfg)
 			side.shroud = cfg.shroud
 		end
 		if cfg.reset_maps then
-			side:override_shroud(side.side, {})
+			side:override_shroud({})
 		end
 		if cfg.fog ~= nil then
 			side.fog = cfg.fog
 		end
 		if cfg.reset_view then
-			side:place_fog(side.side, {}, true)
+			side:place_fog({}, true)
 		end
 		if cfg.shroud_data then
 			side.shroud_data = cfg.shroud_data

src/scripting/game_lua_kernel.cpp

@@ -772,7 +772,7 @@ int game_lua_kernel::intf_override_shroud(lua_State *L)
 			t.clear_shroud(loc);
 		}
 	} else {
-		return luaL_argerror(L, 2, "expected list of locations");
+		return luaW_type_error(L, 2, "list of locations");
 	}
 
 	game_display_->labels().recalculate_shroud();