Retained exploded messages in Keybase Clients for Android and iOS

The Keybase Client for Android before version 5.8.0 and the Keybase Client for iOS before version 5.8.0 fails to properly remove exploded messages initiated by a user if the receiving user places the chat session in the background while the sending user explodes the messages. This could lead to disclosure of sensitive information which was meant to be deleted from the customer's device.