Revert "Autocomplete from GIS list of CRSs.."

This reverts commit dce53630f7.

apps/map/migrations/0051_auto_20180404_0024.py

@@ -1,21 +0,0 @@
-# -*- coding: utf-8 -*-
-# Generated by Django 1.11.6 on 2018-04-04 00:24
-from __future__ import unicode_literals
-
-from django.db import migrations, models
-import django.db.models.deletion
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('map', '0050_auto_20180402_1237'),
-    ]
-
-    operations = [
-        migrations.AlterField(
-            model_name='casestudy',
-            name='coordinate_reference_system',
-            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='gis.PostGISSpatialRefSys'),
-        ),
-    ]