Attempt to fix some errors reported by @singalen

data/lua/wml/animate_unit.lua

@@ -34,7 +34,7 @@ local function add_animation(anim, cfg)
 		)
 	end
 
-	if unit and not wesnoth.is_fogged(wesnoth.current.side, u.loc) then
+	if unit and not wesnoth.is_fogged(wesnoth.current.side, unit.loc) then
 		local primary = helper.get_child(cfg, "primary_attack")
 		local secondary = helper.get_child(cfg, "secondary_attack")
 		local get_attack = get_real_attack

src/scripting/game_lua_kernel.cpp

@@ -463,6 +463,7 @@ static int intf_create_animator(lua_State* L)
 			{"add", impl_add_animation},
 			{"run", impl_run_animation},
 			{"clear", impl_clear_animation},
+			{nullptr, nullptr},
 		};
 		luaL_setfuncs(L, metafuncs, 0);
 		lua_pushstring(L, "__metatable");