Some Errbit messages don't need alerts because they are part of the normal operation of teh fundraising Frontend:

• Any OPTIONS http request
• No route found for "POST /" - This is often used as part of hacking attenpt, sending bogus parameters
• No route found for (everything else than GET/POST/OPTION/HEAD/PUT) - also often part of a hacking attempt
• Tried to access an anonymized Application/Donation. Drop only if route is confirmation
• Some application is still submitting the deprecated form parameter ... Drop only if user agent contains "SemrushBot"

Acceptance Criteria:

• The errors listed don't show up any more.

Implementation Hints:
Implement a Monolog Handler Wrapper (see the HandlerWrapper subclass in this StackOverflow answer).
Wrap the Errbit handler in it when constructing the ErrbitHanlder in LoggerFactory.