downloads fail with CRITICAL 'PostPage'

## Library version

*What's the installed library version ? Check with `instalooter --version`*:

```
instalooter v2.4.4
```

## Environment

*Describe here your environment, including:*

* windows 10
* Python 3.7.9

## Error description - runtime

*If you have an issue at runtime, include the required information below:*

### Reproducible test case

*Are you using the CLI ? If so, include a command that can be used to re-raise the
error, with actual arguments anybody can try:*

```
instalooter user purplemuffinz purplemuffinz -v --traceback
```

### Expected behaviour

*What's supposed to happen ? *
downloads completes

### Actual behaviour

```020-11-20 17:06:17 LazyBoot instalooter.cli[14620] CRITICAL 'PostPage'
Traceback (most recent call last):
File "d:\source\repos\instalooter\.env\lib\site-packages\instalooter\cli\__init__.py", line 173, in main
dlpbar_cls=None if args['--quiet'] else TqdmProgressBar)
File "d:\source\repos\instalooter\.env\lib\site-packages\instalooter\looters.py", line 471, in download
new_only, condition)
File "d:\source\repos\instalooter\.env\lib\site-packages\instalooter\looters.py", line 620, in _fill_media_queue
media = self.get_post_info(media['shortcode'])
File "d:\source\repos\instalooter\.env\lib\site-packages\instalooter\looters.py", line 350, in get_post_info
if 'graphql' in data['entry_data']['PostPage'][0]:
KeyError: 'PostPage'```