[BUG] Article selector preview uses saved selectors instead of submitted ones

[mrnoname1000]

Describe the bug
When previewing article selectors, FreshRSS submits a request to the server with the currently inputted selectors, but the server is ignoring the submitted selectors and instead uses the ones saved in the DB.

To Reproduce
Steps to reproduce the behavior:

1. Type a CSS article selector (and optionally a delete selector) for a feed and submit
2. Change selector without submitting
3. Click the preview button
4. The preview uses the selector(s) submitted in step 1

Expected behavior
The preview should use the selector that is currently inputted in the UI.

Environment information (please complete the following information):

• Device: ThinkPad A485
• OS: Void Linux
• Browser: Firefox 124.0
• FreshRSS version: 1.23.2-dev 1c0b8a7
• Database version: PostgreSQL 16.2
• PHP version: 8.2.7
• Installation type: Docker self hosted

[math-GH]

Thanks for the report.

Duplicate of #6266

Let's close this one to keep the focus on one ticket