This module was filtering out all stations with localizer offset

This module was filtering out all stations with localizer offset
>90deg, even though src/Cockpit/radiostack.cxx has code to deal with
those; as a result, no backcourses were getting through.

This fix allows the common case of backcourses to work again, but
breaks the uncommon case of a runway using the same frequency for two
separate localizers.  That special case will have to be detected
somehow.  Still, this fixes more approaches than it breaks.