x11-wm/lxappearance-obconf: do not pollute RUN_DEPENDS

Currently it includes gmake, pkgconf and intltool as runtime dependencies
due to incorrect variables usage

Replaced the construction with an extra OTHER_DEPENDS variable
accordingly to 5.10.2. RUN_DEPENDS FreeBSD Porter's Handbook

Pull Request: https://github.com/freebsd/freebsd-ports/pull/607