special case 1 to fix vc compilation problem

z:\tmp\nightly-build-6631\build\include\imp\algebra\BoundingBoxD.h(143) : error C2233: 'b_' : arrays of objects containing zero-size arrays are illegal
        z:\tmp\nightly-build-6631\build\include\imp\algebra\BoundingBoxD.h(271) : see reference to class template instantiation 'IMP::algebra::BoundingBoxD<D>' being compiled
        with
        [
            D=0
        ]
        z:\tmp\nightly-build-6631\build\include\imp\algebra\BoundingBoxD.h(272) : see reference to function template instantiation 'IMP::base::Vector<T> IMP::algebra::get_vertices<1>(const IMP::algebra::BoundingBoxD<D> &)' being compiled
        with
        [
            T=IMP::algebra::VectorD<1>,
            D=1
        ]
        z:\tmp\nightly-build-6631\build\include\imp\algebra\BoundingBoxD.h(272) : see reference to function template instantiation 'IMP::base::Vector<T> IMP::algebra::get_vertices<2>(const IMP::algebra::BoundingBoxD<D> &)' being compiled
fix IMP.rmf compilation