Fix #6069: Title screen is black when there are no title sequences

No palette was loaded, so load it in game_init_all.

src/openrct2/game.c

@@ -1494,6 +1494,7 @@ void game_init_all(sint32 mapSize)
     window_staff_list_init_vars();
     scenery_set_default_placement_configuration();
     window_tile_inspector_clear_clipboard();
+    load_palette();
 }
 
 GAME_COMMAND_POINTER* new_game_command_table[GAME_COMMAND_COUNT] = {