This patch fixes a bug in the devel/distcc which becomes obvious when
the port gets built without WITHOUT_GNOME, but when HAVE_GNOME returns ""
For a sample log which shows the breakage by this bug, look at
How-To-Repeat: $ cd /usr/ports/devel/distcc
$ make # Without having GNOME libraries installed
===> Installing for distcc-2.7
install: /tmp/a/ports/devel/distcc/work/distcc-2.7/distccmon-gnome: No such file or directory
*** Error code 71