fix migrations

sapl/comissoes/forms.py

@@ -96,11 +96,14 @@ class CargosComissaoOrdenacaoForm(forms.Form):
     )
     posicao = forms.ChoiceField(
         label='Posição',
-        required=True,
+        required=True
-        choices=choices_posicao()
     )
 
     def __init__(self, *args, **kwargs):
+        super(CargosComissaoOrdenacaoForm, self).__init__(**kwargs)
+        
+        self.fields['posicao'].choices = choices_posicao()
+
         row1 = to_row(
             [('cargo', 12)]
         )
@@ -114,8 +117,6 @@ class CargosComissaoOrdenacaoForm(forms.Form):
             form_actions(label="Atualizar"))
         )
 
-        super().__init__(*args, **kwargs)
-
     def clean(self):
         super(CargosComissaoOrdenacaoForm, self).clean