Add MY_ESP8266_BSSID parameter (#953)

To use this feature, add the following to a sketch, for example
GatewayESP8266MQTTClient:
  const uint8_t bssid[] = {0x00, 0xDE, 0xAD, 0xBE, 0xEF, 0x00};
  #define MY_ESP8266_BSSID bssid

This feature was requested in
https://github.com/mysensors/MySensors/issues/947

core/MyGatewayTransportEthernet.cpp

@@ -122,7 +122,10 @@ bool gatewayTransportInit(void)
 #if defined(MY_IP_ADDRESS)
 	WiFi.config(_ethernetGatewayIP, _gatewayIp, _subnetIp);
 #endif /* End of MY_IP_ADDRESS */
-	(void)WiFi.begin(MY_ESP8266_SSID, MY_ESP8266_PASSWORD);
+#ifndef MY_ESP8266_BSSID
+#define MY_ESP8266_BSSID NULL
+#endif
+	(void)WiFi.begin(MY_ESP8266_SSID, MY_ESP8266_PASSWORD, 0, MY_ESP8266_BSSID);
 	while (WiFi.status() != WL_CONNECTED) {
 		wait(500);
 		MY_SERIALDEVICE.print(F("."));

core/MyGatewayTransportMQTTClient.cpp

@@ -154,7 +154,10 @@ bool gatewayTransportInit(void)
 #if defined(MY_IP_ADDRESS)
 	WiFi.config(_MQTT_clientIp, _gatewayIp, _subnetIp);
 #endif /* End of MY_IP_ADDRESS */
-	(void)WiFi.begin(MY_ESP8266_SSID, MY_ESP8266_PASSWORD);
+#ifndef MY_ESP8266_BSSID
+#define MY_ESP8266_BSSID NULL
+#endif
+	(void)WiFi.begin(MY_ESP8266_SSID, MY_ESP8266_PASSWORD, 0, MY_ESP8266_BSSID);
 #endif /* End of MY_GATEWAY_ESP8266 */
 
 	gatewayTransportConnect();

keywords.txt

@@ -206,5 +206,6 @@ MY_IP_SUBNET_ADDRESS	LITERAL1
 # ESP8266
 MY_ESP8266_SSID	LITERAL1
 MY_ESP8266_PASSWORD	LITERAL1
+MY_ESP8266_BSSID	LITERAL1
 MY_ESP8266_HOSTNAME	LITERAL1
 MY_ESP8266_SERIAL_MODE	LITERAL1