v2.4.2 user not fount for all accounts

## Library version

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

```
instalooter v2.4.2
```

## Environment

*Describe here your environment, including:*

Ubuntu 18.04 LTS
Python 3.6.9

## Error description - installation

I managed to get this working for a bit after creating the user-agent.txt file in the cache folder, but suddenly now it gives "user not found" for any account I throw at it. It works fine for hashtags, but using "user" stopped working:

```
instalooter user elliekimxo ./elliekimxo/ -v -N -T {username}.{datetime} --traceback
2020-06-05 21:29:08 homelab-a instalooter.cli[19096] NOTICE Starting download of `elliekimxo`
2020-06-05 21:29:08 homelab-a instalooter.cli[19096] CRITICAL user not found: 'elliekimxo'
Traceback (most recent call last):
File "/home/evan/.local/lib/python3.6/site-packages/instalooter/cli/__init__.py", line 173, in main
dlpbar_cls=None if args['--quiet'] else TqdmProgressBar)
File "/home/evan/.local/lib/python3.6/site-packages/instalooter/looters.py", line 450, in download
pages_iterator = self.pages() # type: Iterable[Dict[Text, Any]]
File "/home/evan/.local/lib/python3.6/site-packages/instalooter/looters.py", line 723, in pages
it = ProfileIterator.from_username(self._username, self.session)
File "/home/evan/.local/lib/python3.6/site-packages/instalooter/pages.py", line 178, in from_username
raise ValueError("user not found: '{}'".format(username))
ValueError: user not found: 'elliekimxo'
evan@homelab-a:/nfs/instagramrips$

```

## 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 elliekimxo ./elliekimxo/ -v -N -T {username}.{datetime} --traceback
```

### Expected behaviour

It's supposed to work

### Actual behaviour

It suddenly stopped working with user, only works with hashtag