Fix migration running in PostgreSQL

src/NzbDrone.Core/Datastore/Migration/032_health_restored_notification.cs

@@ -8,7 +8,7 @@ namespace NzbDrone.Core.Datastore.Migration
     {
         protected override void MainDbUpgrade()
         {
-            Alter.Table("Notifications").AddColumn("OnHealthRestored").AsBoolean().WithDefaultValue(0);
+            Alter.Table("Notifications").AddColumn("OnHealthRestored").AsBoolean().NotNullable().WithDefaultValue(false);
         }
     }
 }