Merge pull request #3781 from geky/lwip-dtls-speed

lwip: Added delay to dtls handshake test to compensate for local network

features/FEATURE_LWIP/TESTS/mbedmicro-net/host_tests/udp_shotgun.py

@@ -20,6 +20,7 @@ import socket
 import json
 import random
 import itertools
+import time
 from sys import stdout
 from threading import Thread
 from SocketServer import BaseRequestHandler, UDPServer
@@ -42,6 +43,9 @@ class UDPEchoClientHandler(BaseRequestHandler):
             data = ''.join(map(chr, data))
             sock.sendto(data, self.client_address)
 
+            # Sleep a tiny bit to compensate for local network
+            time.sleep(0.01)
+
 
 class UDPEchoClientTest(BaseHostTest):
     def __init__(self):