can import non manifold into 2-Maps (with boundaries)

include/Algo/Import/importMesh.hpp

@@ -110,10 +110,13 @@ bool importMesh(typename PFP::MAP& map, MeshTablesSurface<PFP>& mts)
 			}
 
 			if (good_dart != NIL)
+			{
+				if ((d != map.phi2(d)) && (good_dart != map.phi2(good_dart)) )
 				{
 					map.sewFaces(d, good_dart, false);
 					m.unmarkOrbit<EDGE>(d);
 				}
+			}
 			else
 			{
 				m.unmark(d);