remove unneeded return statement

src/c3nav/mapdata/migrations/0045_merge_areas.py

@@ -23,8 +23,6 @@ def merge_areas(apps, schema_editor):
                 else:
                     break
 
-    return
-
 
 class Migration(migrations.Migration):
 

src/c3nav/mapdata/migrations/0050_auto_20170505_1133.py

@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.4 on 2017-05-05 11:33
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mapdata', '0049_auto_20170505_1125'),
+    ]
+
+    operations = [
+    ]