added comment justifying assignment of None change

layers/dns_layer.py

@@ -164,6 +164,8 @@ def dns_decompress(packet, logger):
         # Next, we must rebuild the DNS packet itself. If we try to have scapy parse either dns_qr1 or dns_qr2, they
         # will look malformed, since neither contains a complete request. Therefore, we must build the entire
         # DNS packet at once. First, we must remove the original DNSQR, since this contains the original request
+        # Need to set qd field to None instead of deleting it to be compatible with scapy 2.5
+        # deleting the qd field in scapy 2.5 causes the qd field to be populated with a question record for example.com
         packet["DNS"].qd = None
 
         # Once the DNSQR is removed, scapy automatically sets the qdcount to 0. Adjust it to 2