WEB_OPTION_OPEN_LINKS_WITH_DEFAULT_APP seems to have no effekt

## Describe the bug
setting `WEB_OPTION_OPEN_LINKS_WITH_DEFAULT_APP` to false does not stop web/ocis to open the link in the default viewer

## Steps to reproduce
1. start ocis with `WEB_OPTION_OPEN_LINKS_WITH_DEFAULT_APP=false`
2. create an .md file
3. create a link of this file
4. open the link in a private tab

## Expected behavior
the user should get the option to open the file in the md viewer or download it

## Actual behavior
md file viewer is opened

## Setup

```console
WEB_OPTION_OPEN_LINKS_WITH_DEFAULT_APP=false OCIS_INSECURE=true PROXY_HTTP_ADDR=0.0.0.0:9200 OCIS_URL=https://host.docker.internal:9200 PROXY_TRANSPORT_TLS_KEY=../ocis.pem PROXY_TRANSPORT_TLS_CERT=../ocis.crt ./bin/ocis server
```

## Additional context
Version 5.0.0-rc.1+954a1c04a0
Web client version 8.0.0-beta.2