Add a notice that you can manually download the dependencies

[MagicalDrizzle]

• package: AppImage
• version: 2021.8.28-treviso-4 Log

HTTPSConnectionPool(host='udomain.dl.sourceforge.net', port=443): Max retries exceeded with url: /project/corefonts/the%20fonts/final/verdan32.exe (Caused by SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1123)')))  File "/tmp/.mount_Bottleeriqq7///usr/local/share/bottles/bottles/utils.py", line 277, in __target
    result = self.task_func(*args, **kwargs)

  File "/tmp/.mount_Bottleeriqq7///usr/local/share/bottles/bottles/backend/dependency.py", line 177, in async_install
    self.__step_cab_extract(

  File "/tmp/.mount_Bottleeriqq7///usr/local/share/bottles/bottles/backend/dependency.py", line 399, in __step_cab_extract
    download = self.__manager.component_manager.download(

  File "/tmp/.mount_Bottleeriqq7///usr/local/share/bottles/bottles/backend/component.py", line 222, in download
    download_url = requests.get(

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/api.py", line 76, in get
    return request('get', url, params=params, **kwargs)

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/sessions.py", line 677, in send
    history = [resp for resp in gen]

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/sessions.py", line 677, in <listcomp>
    history = [resp for resp in gen]

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/sessions.py", line 237, in resolve_redirects
    resp = self.send(

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)

  File "/tmp/.mount_Bottleeriqq7/usr/lib/python3/dist-packages/requests/adapters.py", line 514, in send
    raise SSLError(e, request=request)

Sometimes I won't be able to download dependencies from sourceforge for some reasons (this looks to be some kind of SSL error), but switching to another mirror allows me to download it and put it in /bottles/temp. Maybe you can add a notice for this?