security/zeek: Update to 4.0.3

https://github.com/zeek/zeek/releases/tag/v4.0.3

This release fixes the following bugs:

• Zeek now accepts unset fields in the input data only when the corresponding record field is &optional.
• The version field in ssh.log is now optional and will not be set if we cannot determine the version that was negotiated by the client and server.
• Zeekctl could crash at startup on certain compilers and platforms due to a memory corruption issue in the Broker python bindings.
• The highwayhash submodule was updated to fix a build failure on FreeBSD for PowerPC.

This release deprecates the following functionality:

• The stepping-stone analyzer is marked as deprecated. It was partially marked as deprecated in 2.0, and will be fully removed in v4.1.

Reported by: Tim Wojtulewicz