Hydraulic structure: fix crashing bug happening when we select the section combobox without selecting a reach in the first combobox

src/View/HydraulicStructures/Table.py

@@ -96,14 +96,17 @@ class ComboBoxDelegate(QItemDelegate):
             reach = self._data.hydraulic_structures\
                               .get_for_enabled_reaches(index.row())\
                               .input_reach
-            profiles = list(
-                filter(
-                    lambda p: p.display_name() == text,
-                    reach.reach.profiles
+            if reach is None:
+                value = None
+            else:
+                profiles = list(
+                    filter(
+                        lambda p: p.display_name() == text,
+                        reach.reach.profiles
+                    )
                 )
-            )
 
-            value = profiles[0] if len(profiles) > 0 else None
+                value = profiles[0] if len(profiles) > 0 else None
         else:
             value = text