fix linkcplx higher order

DiffractionGratings/grating2D_scalar.pro

@@ -334,7 +334,7 @@ FunctionSpace {
       { NameOfCoef un;  EntityType NodesOf ; NameOfConstraint Bloch; }
       { NameOfCoef un2; EntityType EdgesOf ; NameOfConstraint Bloch; }
       If (Flag_o2_interp==1)
-        { NameOfCoef un3; EntityType EdgesOf ; NameOfConstraint Bloch; }
+        { NameOfCoef un4; EntityType EdgesOf ; NameOfConstraint Bloch; }
       EndIf
     }
   }