Implemented compatibility handling for AES-256 migration

RNS/Destination.py

@@ -418,7 +418,8 @@ class Destination:
         else:
             plaintext = self.decrypt(packet.data)
             packet.ratchet_id = self.latest_ratchet_id
-            if plaintext != None:
+            if plaintext == None: return False
+            else:
                 if packet.packet_type == RNS.Packet.DATA:
                     if self.callbacks.packet != None:
                         try:
@@ -426,6 +427,8 @@ class Destination:
                         except Exception as e:
                             RNS.log("Error while executing receive callback from "+str(self)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
 
+                return True
+
     def incoming_link_request(self, data, packet):
         if self.accept_link_requests:
             link = RNS.Link.validate_request(self, data, packet)