minor fix after merging

libsession/src/main/java/org/session/libsession/messaging/StorageProtocol.kt

@@ -81,7 +81,7 @@ interface StorageProtocol {
     fun getReceivedMessageTimestamps(): Set<Long>
     fun addReceivedMessageTimestamp(timestamp: Long)
     // Returns the IDs of the saved attachments.
-    fun persist(attachments: List<Attachment>): List<String>
+    fun persist(attachments: List<Attachment>): List<Long>
     fun insertMessageOutbox(message: Message)
     fun insertMessageInbox(message: Message)
     fun setErrorMessage(message: Message, error: Exception)

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/MessageReceiverHandler.kt

@@ -91,7 +91,7 @@ fun MessageReceiver.handleVisibleMessage(message: VisibleMessage, proto: SignalS
         }
     }
     val attachmentIDs = storage.persist(attachments)
-    message.attachmentIDs = attachmentIDs as ArrayList<String>
+    message.attachmentIDs = attachmentIDs as ArrayList<Long>
     var attachmentsToDownload = attachmentIDs
     // Update profile if needed
     val newProfile = message.profile