correct boot loader filename

sandeepmistry · facchinm · commit 9398c530f585 · 2018-08-29T16:31:06.000+02:00
diff --git a/boards.txt b/boards.txt
@@ -41,4 +41,4 @@ mkrvidor4000.build.variant=mkrvidor4000
 mkrvidor4000.build.vid=0x2341
 mkrvidor4000.build.pid=0x8056
 mkrvidor4000.bootloader.tool=openocd
-mkrvidor4000.bootloader.file=mkrvidor4000/samd21_sam_ba_arduino_mkrvidor.bin
+mkrvidor4000.bootloader.file=mkrvidor4000/samd21_sam_ba_arduino_mkrvidor4000.bin
