security/zeek: Update to 3.0.6 and address multiple vulnerabilites:

https://raw.githubusercontent.com/zeek/zeek/v3.0.6/NEWS

• Fix buffer over-read in Ident analyzer
• Fix SSL scripting error leading to uninitialized field access and memory leak
• Fix POP3 analyzer global buffer over-read
• Fix potential stack overflows due to use of Variable-Length-Arrays

Other changes since 3.0.5 include:

• Fix unusable subscriber.poll() method in Broker Python bindings
• Fix uninitialized field access in ssl/log-hostcerts-only.zeek
• Fix missing default function for Kerberos constant-lookup-tables
• Fix cloning of TypeType values
• Remove misleading error message on empty bloomfilter lookup
• Fix misc/stats.zeek skipping log entry on termination

MFH: 2020Q2