MFH: r553441

security/modsecurity3: include unicode.mapping in package

This is included in the distribution and referenced in the default
configuration that's installed, but hasn't been included in the package. Do
so now.

PR: 250669
Submitted by: Marius Halden <marius halden modirum com> (maintainer)

Approved by: ports-secteam (implicit, packaging fix)