Geometry, Results: Fix HS display whene not associated.

src/View/Geometry/PlotKPZ.py

@@ -191,7 +191,10 @@ class PlotKPZ(PamhyrPlot):
     def draw_profiles_hs(self, reach):
         lhs = filter(
             lambda hs: hs._input_reach.reach is reach,
-            self._study.river.hydraulic_structures.lst
+            filter(
+                lambda hs: hs._input_reach is not None,
+                self._study.river.hydraulic_structures.lst
+            )
         )
 
         for hs in lhs: