fix migrations

sapl/base/migrations/0022_auto_20180828_1439.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.13 on 2018-08-28 17:39
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('base', '0021_appconfig_esfera_federacao'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='appconfig',
+            name='esfera_federacao',
+            field=models.CharField(blank=True, choices=[('M', 'Municipal'), ('E', 'Estadual'), ('F', 'Federal')], default='', max_length=1, verbose_name='Esfera Federação'),
+        ),
+    ]

sapl/base/models.py

@@ -86,7 +86,7 @@ class AppConfig(models.Model):
     esfera_federacao = models.CharField(
         max_length=1,
         blank=True,
-        null=True,
+        default = "",
         verbose_name=_('Esfera Federação'),
         choices=ESFERA_FEDERACAO_CHOICES)