[Bug]: Per-account connections settings don't apply/work after reboot

### ⚠️ Before submitting, please verify the following: ⚠️

- [x] This is a **bug**, not a question or a configuration issue.
- [x] This issue is **not** already reported on Github (I've searched it).
- [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

Configuring an account proxy configuration does not work after reboot until the user manually changes the proxy selection.

The connection settings are still shown in the UI and the `nextcloud.cfg` file still contains the proxy configuration, but the connection does not appear to be using them. So, for some reason, after reboot the Nextcloud Desktop agent is not using its global or the account connection settings.

### Steps to reproduce

1. Configure account to "Use global settings" (that has a proxy configuration)
2. Reboot system
3. Connection is broken
4. Open account connection settings
5. Confirm that it is configured to "Use global settings"
6. Confirm that `nextcloud.cfg` contains the proxy configuration
7. Switch account to "No proxy" -> Connection restored
8. Switch account to "Use global settings" -> Connection restored, still

### Expected behavior

Account connection settings should work after reboot without manually reapplying.

### Which files are affected by this bug

All files

### Operating system

Linux

### Which version of the operating system you are running.

Ubuntu 22.04

### Package

Distro package manager

### Nextcloud Server version

28.0.7.4

### Nextcloud Desktop Client version

3.14.2

### Is this bug present after an update or on a fresh install?

Updated to a major version (ex. 3.3.6 to 3.4.0)

### Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

### Are you using an external user-backend?

- [ ] Default internal user-backend
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

N/A

### Additional info

_No response_