security/zeek: Update to 5.0.4

https://github.com/zeek/zeek/releases/tag/v5.0.4

This release fixes the following potential DoS vulnerabilities:

• A specially-crafted series of HTTP 0.9 packets can cause Zeek to spend large amounts of time processing the packets.
• A specially-crafted FTP packet can cause Zeek to spend large amounts of time processing the command.
• A specially-crafted IPv6 packet can cause Zeek to overflow memory and potentially crash.

This release fixes the following bugs:

• Fix a potential stall in Broker’s internal data pipeline.

Reported by: Tim Wojtulewicz
Security: ???

(cherry picked from commit a940eea46e391fb788b2663c20ccdf6a8554fe4f)