Modified WiFiMulti to work with FreeRTOS

[richteel]

Fixed an issue that I described in the discussion, #1873.

I replaced delay(5); in WiFiMulti.cpp with the following code and it works fine with FreeRTOS.

`unsigned long tWifiDelayForRtos_start = millis();
while (millis()-tWifiDelayForRtos_start <= 5) {
   if(millis()<tWifiDelayForRtos_start) {
	// millis wrapped around to zero
	tWifiDelayForRtos_start = millis();
   }
}`

[richteel]

astyle failing. Canceling request to make changes to indentation characters.