When filtering with regular expressions, the 'does not match' option does not always function as expected

[TheWitness]

Describe the bug

The regular expression logic available in the Cacti log page does not allow negative searches properly.

To Reproduce

Steps to reproduce the behavior:

1. Go to the Log tab

2. Set a filter for message levels Warning or above (Warning++)

3. Try to exclude certain lines with a negation regular expression

4. See error

Expected behavior

Cacti should have a way to be able to remove expressions by regular expression.