exception raised on startup if the cache file is corrupted

[flaviogrossi]

If the file containing the persisted cache on disk is corrupted (empty file in this case), the following error is raised:

    ** (EXIT) an exception was raised:
        ** (MatchError) no match of right hand side value:
    {:error, {%ArgumentError{message: "/tmp/tus_cache.tab is not a valid PersistentEts file: {:read_error, {:not_a_log_file, '/tmp/tus_cache.tab'}}"}, [{PersistentEts.TableManager, :open_table, 3, [file: 'lib/table_manager.ex', line: 180]}, {PersistentEts.TableManager, :init, 1, [file: 'lib/table_manager.ex', line: 72]}, {:gen_server, :init_it, 2, [file: 'gen_server.erl', line: 374]}, {:gen_server, :init_it, 6, [file: 'gen_server.erl', line: 342]}, {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}]}}
            (persistent_ets) lib/persistent_ets.ex:75: PersistentEts.new/3
            (tus_plug) lib/tus_plug/cache.ex:54: TusPlug.Cache.init/1
            (stdlib) gen_server.erl:374: :gen_server.init_it/2
            (stdlib) gen_server.erl:342: :gen_server.init_it/6
            (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3```

[xadhoom]

For some reason :dets auto repair fails, maybe we can try harder and delete the file if autorepair fails