fix migration

fet2020/tasks/migrations/0002_alter_task_options_task_slug_task_slug_id_and_more.py

@@ -33,20 +33,22 @@ class Migration(migrations.Migration):
             name='task',
             options={'ordering': ('task_list', django.db.models.expressions.OrderBy(django.db.models.expressions.F('due_date'), descending=True, nulls_first=True)), 'verbose_name': 'Aufgabe', 'verbose_name_plural': 'Aufgaben'},
         ),
+        # remove unique=True to set value, and then set option unique=True
         migrations.AddField(
             model_name='task',
             name='slug',
-            field=models.SlugField(blank=True, unique=True),
+            field=models.SlugField(blank=True),
         ),
         migrations.AddField(
             model_name='task',
             name='slug_id',
             field=models.CharField(default=fet2020.utils.create_random_id, editable=False, max_length=8, unique=True),
         ),
+        # remove unique=True to set value, and then set option unique=True
         migrations.AddField(
             model_name='tasklist',
             name='shortterm',
-            field=models.CharField(blank=True, max_length=128, unique=True),
+            field=models.CharField(blank=True, max_length=128),
         ),
         migrations.AlterField(
             model_name='task',
@@ -79,4 +81,15 @@ class Migration(migrations.Migration):
             },
         ),
         migrations.RunPython(forwards_func),
+        # unique=True after setting value
+        migrations.AlterField(
+            model_name='task',
+            name='slug',
+            field=models.SlugField(blank=True, unique=True),
+        ),
+        migrations.AlterField(
+            model_name='tasklist',
+            name='shortterm',
+            field=models.CharField(blank=True, max_length=128, unique=True),
+        ),
     ]