Stop crash on binary path division (flatpak)

Not apparent without _GLIBCXX_ASSERTIONS
Fixes inbox#397

Cherry picked from ef3963e2 (1.0alpha)

src/livarot/ShapeMisc.cpp

@@ -393,7 +393,7 @@ Shape::ConvertToFormeNested (Path * dest, int nbP, Path * *orig, int /*wildPath*
               parentContour = GPOINTER_TO_INT(swdData[askTo].misc);
               parentContour-=1; // pour compenser le decalage
           }
-          childEdge = getPoint(fi).incidentEdge[FIRST];
+          childEdge = getPoint(fi % numberOfPoints()).incidentEdge[FIRST];
         }
       }
       lastPtUsed = fi + 1;