ports/184120: Fix x11-toolkits/pure-tk build

[sunpoet at FreeBSD.org]

Synopsis: Fix x11-toolkits/pure-tk build

Responsible-Changed-From-To: freebsd-ports-bugs->sunpoet
Responsible-Changed-By: sunpoet
Responsible-Changed-When: Wed Nov 20 19:30:56 UTC 2013
Responsible-Changed-Why: 
I'll take it.

http://www.freebsd.org/cgi/query-pr.cgi?pr=184120