Bug#304679: i386 port should not compile code for i686

[Alberto <coleccionspam@terra.es>]

Here you are:

strings libqt-mt.so.3.3.4 | grep full-config
writes:
i586 Linux g++-3.* full-config

and strings kdewidgets.so | grep full-config
buildkey=i586 Linux g++-3.* full-config