Results: Fix river loading reachs creation.

src/Model/Results/River/River.py

@@ -393,7 +393,7 @@ class Reach(SQLSubModel):
 class River(SQLSubModel):
     _sub_classes = [Reach]
 
-    def __init__(self, study, parent):
+    def __init__(self, study, parent, init=True):
         super(River, self).__init__(
             id=-1, status=study.status,
             owner_scenario=study.status.scenario.id
@@ -404,6 +404,7 @@ class River(SQLSubModel):
 
         # Dict with timestamps as key
         self._reachs = []
+        if init:
             for i, _ in enumerate(self._study.river.enable_edges()):
                 self.add(i)
 
@@ -458,7 +459,7 @@ class River(SQLSubModel):
         study = data["study"]
         parent = data["parent"]
 
-        new_river = cls(study, parent)
+        new_river = cls(study, parent, init=False)
 
         for reach in study.river.reachs():
             data["reach"] = reach.reach