CI fix for WiFiUdpNtpClient example

examples/WiFiUdpNtpClient/WiFiUdpNtpClient.ino

@@ -170,7 +170,7 @@ void loop() {
 }
 
 // send an NTP request to the time server at the given address
-unsigned long sendNTPpacket(IPAddress& address) {
+void sendNTPpacket(IPAddress& address) {
   //Serial.println("1");
   // set all bytes in the buffer to 0
   memset(packetBuffer, 0, NTP_PACKET_SIZE);