text: Title: unknown bug i cant able to figure it out no detailed info available ...when im trying to migrate this bug is popped always
  Body: Traceback (most recent call last):
    File "/usr/local/bin/aerich", line 8, in <module>
      sys.exit(main())
    File "/usr/local/lib/python3.9/site-packages/aerich/cli.py", line 258, in main
      cli()
    File "/usr/local/lib/python3.9/site-packages/click/core.py", line 829, in __call__
      return self.main(*args, **kwargs)
    File "/usr/local/lib/python3.9/site-packages/click/core.py", line 782, in main
      rv = self.invoke(ctx)
    File "/usr/local/lib/python3.9/site-packages/click/core.py", line 1259, in invoke
      return _process_result(sub_ctx.command.invoke(sub_ctx))
    File "/usr/local/lib/python3.9/site-packages/click/core.py", line 1066, in invoke
      return ctx.invoke(self.callback, **ctx.params)
    File "/usr/local/lib/python3.9/site-packages/click/core.py", line 610, in invoke
      return callback(*args, **kwargs)
    File "/usr/local/lib/python3.9/site-packages/click/decorators.py", line 21, in new_func
      return f(get_current_context(), *args, **kwargs)
    File "/usr/local/lib/python3.9/site-packages/aerich/cli.py", line 33, in wrapper
      loop.run_until_complete(f(*args, **kwargs))
    File "/usr/local/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete
      return future.result()
    File "/usr/local/lib/python3.9/site-packages/aerich/cli.py", line 91, in migrate
      ret = await command.migrate(name)
    File "/usr/local/lib/python3.9/site-packages/aerich/__init__.py", line 115, in migrate
      return await Migrate.migrate(name)
    File "/usr/local/lib/python3.9/site-packages/aerich/migrate.py", line 130, in migrate
      cls.diff_models(cls._last_version_content, new_version_content)
    File "/usr/local/lib/python3.9/site-packages/aerich/migrate.py", line 211, in diff_models
      table = change[0][1].get("through")
  AttributeError: 'str' object has no attribute 'get'
  