ports/78782: [Maintainer] www/gatling: update to 0.7

[Thomas-Martin Seck]

* Michael Johnson (ahze at FreeBSD.org):

> Does not compile on 4.x
...
> Does not compile on 5.x
...

www/gatling is very closely tied to devel/libowfat and gatling-0.7
requires libowfat-0.22 to build. Please check whether you have
libowfat-0.22 installed; it builds here on RELENG_5 and RELENG_4.