Set Megatronics baud rate to 115200

Fix #9092

Marlin/src/config/examples/RepRapWorld/Megatronics/Configuration.h

@@ -124,7 +124,7 @@
  *
  * :[2400, 9600, 19200, 38400, 57600, 115200, 250000, 500000, 1000000]
  */
-#define BAUDRATE 250000
+#define BAUDRATE 115200
 
 // Enable the Bluetooth serial interface on AT90USB devices
 //#define BLUETOOTH