Ignore duplicate messages

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

squinnondation/messages.py

@@ -208,7 +208,10 @@ class DataTLV(TLV):
         TODO: Check that the tuple (sender_id, nonce) is unique to avoid duplicates.
         """
         msg = self.data.decode('UTF-8')
-        squirrel.add_message(msg)
+        if not squirrel.receive_message_from(msg, self.sender_id, self.nonce):
+            # The message was already received
+            return
+
         nickname_match = re.match("(.*): (.*)", msg)
         if nickname_match is None:
             squirrel.send_packet(sender, Packet.construct(WarningTLV.construct(