Fix max upload size for modwifi and nodemcu (#314)

Author: igrr

hardware/esp8266com/esp8266/boards.txt

@@ -134,7 +134,8 @@ modwifi.name=Olimex MOD-WIFI-ESP8266(-DEV)
 modwifi.upload.tool=esptool
 modwifi.upload.speed=115200
 modwifi.upload.resetmethod=ck
-modwifi.upload.maximum_size=2097152
+modwifi.upload.maximum_size=983040
+modwifi.upload.maximum_data_size=81920
 modwifi.upload.wait_for_upload_port=true
 modwifi.serial.disableDTR=true
 modwifi.serial.disableRTS=true
@@ -185,7 +186,8 @@ nodemcu.name=NodeMCU (ESP8266 ESP-12 Module)
 nodemcu.upload.tool=esptool
 nodemcu.upload.speed=115200
 nodemcu.upload.resetmethod=ck
-nodemcu.upload.maximum_size=4194304
+nodemcu.upload.maximum_size=983040
+nodemcu.upload.maximum_data_size=81920
 nodemcu.upload.wait_for_upload_port=true
 nodemcu.serial.disableDTR=true
 nodemcu.serial.disableRTS=true