Add required on_delete parameters for Dj2.0 compatibility

allianceauth/optimer/migrations/0004_on_delete.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.5 on 2017-09-28 02:16
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('optimer', '0003_make_strings_more_stringy'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='optimer',
+            name='eve_character',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='eveonline.EveCharacter'),
+        ),
+    ]

allianceauth/optimer/models.py

@@ -17,7 +17,7 @@ class OpTimer(models.Model):
     operation_name = models.CharField(max_length=254, default="")
     fc = models.CharField(max_length=254, default="")
     post_time = models.DateTimeField(default=timezone.now)
-    eve_character = models.ForeignKey(EveCharacter)
+    eve_character = models.ForeignKey(EveCharacter, null=True, on_delete=models.SET_NULL)
 
     def __str__(self):
         return self.operation_name