Do not show python traceback when esptool fails (#8603)
Do not show python traceback when esptool fails (#8603)

Path separator already handled by python
Empty strings are false, implicitly checking for length
sticilface/Arduino,esp8266/Arduino,esp8266/Arduino,esp8266/Arduino,sticilface/Arduino,sticilface/Arduino,sticilface/Arduino,esp8266/Arduino,sticilface/Arduino,esp8266/Arduino