Fixed an issue where only the first sync config message would be processed

Session/Meta/AppDelegate.swift

@@ -14,8 +14,13 @@ extension AppDelegate {
             let job = MessageSendJob(message: configurationMessage, destination: destination)
             JobQueue.shared.add(job, using: transaction)
         }
+        
+        // Only update the 'lastConfigurationSync' timestamp if we have done the first sync (Don't want
+        // a new device config sync to override config syncs from other devices)
+        if userDefaults[.hasSyncedInitialConfiguration] {
             userDefaults[.lastConfigurationSync] = Date()
         }
+    }
 
     func forceSyncConfigurationNowIfNeeded() -> Promise<Void> {
         guard Storage.shared.getUser()?.name != nil,

SessionMessagingKit/Sending & Receiving/MessageReceiver+Handling.swift

@@ -190,15 +190,23 @@ extension MessageReceiver {
         SNLog("Configuration message received.")
         let storage = SNMessagingKitConfiguration.shared.storage
         let transaction = transaction as! YapDatabaseReadWriteTransaction
+        let messageSentTimestamp: TimeInterval = TimeInterval((message.sentTimestamp ?? 0) / 1000)   // `sentTimestamp` is in ms
+        let lastConfigTimestamp: TimeInterval = (UserDefaults.standard[.lastConfigurationSync]?.timeIntervalSince1970 ?? Date(timeIntervalSince1970: 0).timeIntervalSince1970)
+        
         // Profile
         var userProfileKey: OWSAES256Key? = nil
         if let profileKey = message.profileKey { userProfileKey = OWSAES256Key(data: profileKey) }
         updateProfileIfNeeded(publicKey: userPublicKey, name: message.displayName, profilePictureURL: message.profilePictureURL,
             profileKey: userProfileKey, sentTimestamp: message.sentTimestamp!, transaction: transaction)
-        // Initial configuration sync
+        
+        if !UserDefaults.standard[.hasSyncedInitialConfiguration] || messageSentTimestamp > lastConfigTimestamp {
             if !UserDefaults.standard[.hasSyncedInitialConfiguration] {
                 UserDefaults.standard[.hasSyncedInitialConfiguration] = true
                 NotificationCenter.default.post(name: .initialConfigurationMessageReceived, object: nil)
+            }
+            
+            UserDefaults.standard[.lastConfigurationSync] = Date(timeIntervalSince1970: messageSentTimestamp)
+            
             // Contacts
             for contactInfo in message.contacts {
                 let sessionID = contactInfo.publicKey!