Robustifie code effacement décision

app/but/jury_but.py

@@ -865,10 +865,15 @@ class DecisionsProposeesAnnee(DecisionsProposees):
                 self.etud.id, self.formsemestre.id
             )
             for dec_ue in self.decisions_ues.values():
-                if dec_ue.formsemestre.id == self.formsemestre.id:
+                if (
+                    dec_ue
+                    and self.formsemestre
+                    and dec_ue.formsemestre.id == self.formsemestre.id
+                ):
                     dec_ue.erase()
         else:
             for dec_ue in self.decisions_ues.values():
+                if dec_ue:
                     dec_ue.erase()
 
             if self.formsemestre_impair: