inhibit verbose to RSS output

[gloschtla]

Describe the bug
sometimes the RSS bridge is not working well. Then the RSS feed posts something unwanted: Error 404 or Error 500. There should be an option to disable verbose.

To Reproduce
Steps to reproduce the behavior:

1. connect the RSS output to a bot that posts the latest RSS entry into a channel.
2. provoke the server to fail (not available 404, or internal server error 500)
3. the channel will get a new post with Bridge returned error 500! (number) and the posted URL contains the RSSfeed instead of the URL of the missing new RSS entry.

Expected behavior
when server errors occurs, please do not post anything into RSS output

Screenshots
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Additional context
This happened with an alternative RSS bridge instance, with Filter in use.