Client certificate configuration is lost and no reconfiguration is triggered

### ⚠️ Before posting ⚠️

- [x] This is a **bug**, not a question or an enhancement.
- [x] I've [searched for similar issues](https://github.com/nextcloud/android/issues) and didn't find a duplicate.
- [x] I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/).

### Steps to reproduce

1. Configure (web) server to require client certificate
2. install valid client certificate on Android device
3. install a second "invalid" certificate (so that there is something todo on the "select cert" dialog)
4. start the app, connect to server and select the valid certificate when asked
5. ... wait ... I don't know what triggers the problem, could be an app (or os) update
6. open the app, the application is not connected to the server

this is the first problem. the application is no longer using the certificate and is not able to reach the server.

The follow up problem is that there is no "easy" way to reconnect. the app is not asking for the certificate unless I do the following

1. goto app drawer in the settings
2. kill the app
3. open the app
4. for less than a second a certificate dialog is shown and if you are fast enough you can select the certificate

### Expected behaviour

a) the application should not "forget" the configured certificate

b) the "select certificate" dialog should not be closed automatically (or at least give enough time to select and save the selection)

c) it should not be required to kill the app to reconnect

### Actual behaviour

see steps to reproduce

### Android version

16

### Device brand and model

Pixel 8a

### Stock or custom OS?

Stock

### Nextcloud android app version

33.0.1

### Nextcloud server version

Hub26

### Using a reverse proxy?

Yes

### Android logs

_No response_

### Server error logs

```bash

```

### Additional information

_No response_