Add blocking of traffic caused by snort rule 58741

[cweibel]

Changes proposed in this pull request:

• Second time we've received an alert in the last 6 months for this, just going to block the traffic based on this rule instead of alerting and investigating
• Mutes the existing alert rule and adds a drop rule with a unique identifier which is the original rule number with 3 zeroes appended to keep it out of the number sequences assigned by snort maintainers: 58741000

security considerations

Blocks traffic instead of simply alerting