[Bug]: provide a better error message than Network Error: # on nextcloudcmd

[trajano]

⚠️ 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 and Desktop Releases for supported versions.
• [ ] I agree to follow Nextcloud's Code of Conduct

Bug description

The error message on the BulkPropagatorJob looks like this

  Could not complete propagation of ... by OCC::BulkPropagatorJob(0x557c662c70) with status OCC::SyncFileItem::NormalError and error: "Network error: 2"

The problem is it's just hard to figure out what the 2 or 5 or whatever means.

Steps to reproduce

It's a log event.

Expected behavior

Something like

Network error: 2: got a HTTP 502 error code from the server"

Which files are affected by this bug

https://github.com/nextcloud/desktop/blob/e32ff9d6a97de898d430b15241b06af0fcac6d6a/src/libsync/bulkpropagatorjob.cpp#L508

Operating system

Linux

Which version of the operating system you are running.

Raspbian

Package

Distro package manager

Nextcloud Server version

31.0.6

Nextcloud Desktop Client version

Nextcloud version 3.7.3git

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

Updated from a minor version (ex. 3.4.2 to 3.4.4)

Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

Are you using an external user-backend?

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

Nextcloud Server logs

Additional info

https://github.com/nextcloud/desktop/issues/7001