ports/156912: Fix port: mail/thunderbird occasionally breaks with gmake-3.82

[edwin at FreeBSD.org]

Synopsis: Fix port: mail/thunderbird occasionally breaks with gmake-3.82

Responsible-Changed-From-To: freebsd-ports-bugs->gecko
Responsible-Changed-By: edwin
Responsible-Changed-When: Mon May 9 19:10:17 UTC 2011
Responsible-Changed-Why: 
Over to maintainer (via the GNATS Auto Assign Tool)

http://www.freebsd.org/cgi/query-pr.cgi?pr=156912