fix chat_id fields

aggregator/migrations/0003_auto_20190128_0048.py

@@ -0,0 +1,23 @@
+# Generated by Django 2.1.5 on 2019-01-27 21:48
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('aggregator', '0002_remove_aggregationsource_last_id'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='aggregationsource',
+            name='chat_id',
+            field=models.CharField(db_index=True, max_length=64),
+        ),
+        migrations.AlterField(
+            model_name='chat',
+            name='chat_id',
+            field=models.CharField(db_index=True, max_length=64),
+        ),
+    ]