Changes maximum upload size to valid size

Author: Pontus Oldberg

hardware/esp8266com/esp8266/boards.txt

@@ -324,7 +324,7 @@ esp210.name=SweetPea ESP-210
 esp210.upload.tool=esptool
 esp210.upload.speed=115200
 esp210.upload.resetmethod=ck
-esp210.upload.maximum_size=4194304
+esp210.upload.maximum_size=1044464
 esp210.upload.wait_for_upload_port=true
 esp210.serial.disableDTR=true
 esp210.serial.disableRTS=true