www/apache24: Update to 2.4.27

• Bugfix update to 2.4.27
• Fix build with LibreSSL [1]
• Add brotli compression option
• Add pkg-message for 10.3 base-ssl users
• HTTP/2 is production ready, default enable
  • warn users of 10.3 for mod_http2/OpenSSL 1.0.1

[1] https://bz.apache.org/bugzilla/show_bug.cgi?id=61184

PR: 220160 [1]
Reported by: Markus Kohlmeyer <rootservice@gmail.com>
Reviewed by: ohauer (hat)
Approved by: ohauer (hat)
Differential Revision: https://reviews.freebsd.org/D11285