esp8266/Makefile: Enable --verify option for esptool.py write_flash.

Based on my experience, there's rather non-zero chance to have an image be
flashed incorrectly. As --verify option is now works well in teh latest
esptool.py, enable it by default.

esp8266/Makefile

@@ -167,7 +167,7 @@ $(BUILD)/frozen.c: $(wildcard $(SCRIPTDIR)/*) $(CONFVARS_FILE)
 
 deploy: $(BUILD)/firmware-combined.bin
 	$(ECHO) "Writing $< to the board"
-	$(Q)esptool.py --port $(PORT) --baud $(BAUD) write_flash --flash_size=8m 0 $<
+	$(Q)esptool.py --port $(PORT) --baud $(BAUD) write_flash --verify --flash_size=8m 0 $<
 	#$(Q)esptool.py --port $(PORT) --baud $(BAUD) write_flash --flash_size=8m 0 $(BUILD)/firmware.elf-0x00000.bin 0x9000 $(BUILD)/firmware.elf-0x0[1-f]000.bin
 
 reset: