[polyhedron] correct a condition and make sure the contribution test is less permissive
[polyhedron] correct a condition and make sure the contribution test is less permissive

mehdi-benallegue/sch-core,jrl-umi3218/sch-core,mehdi-benallegue/sch-core,jrl-umi3218/sch-core,mehdi-benallegue/sch-core,jrl-umi3218/sch-core