Fix possible NullRef in Email Encryption migration

src/NzbDrone.Core.Test/Datastore/Migration/201_email_encryptionFixture.cs

@@ -81,6 +81,35 @@ namespace NzbDrone.Core.Test.Datastore.Migration
             items.First().ConfigContract.Should().Be("EmailSettings");
             items.First().Settings.UseEncryption.Should().Be((int)EmailEncryptionType.Always);
         }
+
+        [Test]
+        public void should_use_defaults_when_settings_are_empty()
+        {
+            var db = WithMigrationTestDb(c =>
+            {
+                c.Insert.IntoTable("Notifications").Row(new
+                {
+                    OnGrab = true,
+                    OnDownload = true,
+                    OnUpgrade = true,
+                    OnHealthIssue = true,
+                    IncludeHealthWarnings = true,
+                    OnRename = true,
+                    Name = "Mail Sonarr",
+                    Implementation = "Email",
+                    Tags = "[]",
+                    Settings = new { }.ToJson(),
+                    ConfigContract = "EmailSettings"
+                });
+            });
+
+            var items = db.Query<NotificationDefinition201>("SELECT * FROM \"Notifications\"");
+
+            items.Should().HaveCount(1);
+            items.First().Implementation.Should().Be("Email");
+            items.First().ConfigContract.Should().Be("EmailSettings");
+            items.First().Settings.UseEncryption.Should().Be((int)EmailEncryptionType.Preferred);
+        }
     }
 
     public class NotificationDefinition201

src/NzbDrone.Core/Datastore/Migration/201_email_encryption.cs

@@ -31,7 +31,7 @@ namespace NzbDrone.Core.Datastore.Migration
                         var id = reader.GetInt32(0);
                         var settings = Json.Deserialize<JObject>(reader.GetString(1));
 
-                        settings["useEncryption"] = settings["requireEncryption"].ToObject<bool>() ? 1 : 0;
+                        settings["useEncryption"] = settings.Value<bool>("requireEncryption") ? 1 : 0;
                         settings["requireEncryption"] = null;
 
                         updated.Add(new
@@ -43,7 +43,7 @@ namespace NzbDrone.Core.Datastore.Migration
                 }
             }
 
-            var updateSql = $"UPDATE \"Notifications\" SET \"Settings\" = @Settings WHERE \"Id\" = @Id";
+            var updateSql = "UPDATE \"Notifications\" SET \"Settings\" = @Settings WHERE \"Id\" = @Id";
             conn.Execute(updateSql, updated, transaction: tran);
         }
     }