Merge pull request #1725 from ulikoehler/patch-1

Fix case-insensitive ESPDuino file name

Author: Links2004

boards.txt

@@ -248,7 +248,7 @@ espduino.build.mcu=esp8266
 espduino.build.f_cpu=80000000L
 espduino.build.board=ESP8266_ESP13
 espduino.build.core=esp8266
-espduino.build.variant=espduino
+espduino.build.variant=ESPDuino
 espduino.build.flash_mode=dio
 espduino.build.flash_size=4M
 espduino.build.flash_freq=40