WIP: make new property lastChangeTimestampsMs optional

SessionMessagingKit/Database/Models/DisappearingMessageConfiguration.swift

@@ -51,7 +51,7 @@ public struct DisappearingMessagesConfiguration: Codable, Identifiable, Equatabl
     public let isEnabled: Bool
     public let durationSeconds: TimeInterval
     public var type: DisappearingMessageType?
-    public let lastChangeTimestampMs: Int64
+    public let lastChangeTimestampMs: Int64?
     
     // MARK: - Relationships
     

SessionMessagingKit/Messages/Message.swift

@@ -73,7 +73,7 @@ public class Message: Codable {
         }
         
         proto.setExpirationTimer(UInt32(disappearingMessagesConfiguration.durationSeconds))
-        proto.setLastDisappearingMessageChangeTimestamp(UInt64(disappearingMessagesConfiguration.lastChangeTimestampMs))
+        proto.setLastDisappearingMessageChangeTimestamp(UInt64(disappearingMessagesConfiguration.lastChangeTimestampMs ?? 0))
         
         if disappearingMessagesConfiguration.isEnabled, let type = disappearingMessagesConfiguration.type {
             proto.setExpirationType(type.toProto())

SessionMessagingKit/Sending & Receiving/MessageReceiver.swift

@@ -350,7 +350,10 @@ public enum MessageReceiver {
             .fetchOne(db, id: threadId)
             .defaulting(to: DisappearingMessagesConfiguration.defaultWith(threadId))
         
-        guard protoLastChangeTimestampMs > localConfig.lastChangeTimestampMs else { return }
+        guard
+            let localLastChangeTimestampMs = localConfig.lastChangeTimestampMs,
+            protoLastChangeTimestampMs > localLastChangeTimestampMs
+        else { return }
         
         let durationSeconds: TimeInterval = proto.hasExpirationTimer ? TimeInterval(proto.expirationTimer) : 0
         let isEnable: Bool = (durationSeconds != 0)