When "USES= php:ext" is set into the Makefile, there is a following
warning:"@exec is deprecated, please use @[pre|post][un]exec" [1][2]
After change exec and unexec to post* it works again correctly

[1] https://github.com/freebsd/freebsd-ports/blob/master/CHANGES#L407
[2] https://www.freebsd.org/doc/en/books/porters-handbook/book.html#plist-keywords-base-exec

Approved by: portmgr (mat)
Approved my: rene (mentor)
Differential Revision: https://reviews.freebsd.org/D12215