lang/php56: update 5.6.21 -> 5.6.22 [1] plus minor fixup

• Fix MAILHEAD patch to match the new version of the patch. The distinfo currently matches the php-5.5.x-mail-header.patch.old patch. [2]

PR: 209779 [1]
PR: 208072 [2]
Reported by: Fabiano Sidler <fabianosidler@swissonline.ch> [1]
Reported by: Vladislav V. Prodan <admin@support.od.ua> [2]
Approved by: ports-secteam (with hat)
Security: CVE-2013-7456
Security: CVE-2016-5093
Security: CVE-2016-5094
Security: CVE-2016-5096
Security: https://vuxml.FreeBSD.org/freebsd/6b110175-246d-11e6-8dd3-002590263bf5.html
MFH: 2016Q2