tools/pydfu.py: Call set_configuration() on fresh USB device object.
tools/pydfu.py: Call set_configuration() on fresh USB device object.

This call is required before using the device (some operating systems don't
need it but others do).  Fixes issue #3476.

MrSurly/micropython,blazewicz/micropython,pfalcon/micropython,dmazzella/micropython,trezor/micropython,swegener/micropython,tobbad/micropython,infinnovation/micropython,tobbad/micropython,pozetroninc/micropython,selste/micropython,pramasoul/micropython,tralamazza/micropython,tralamazza/micropython,kerneltask/micropython,bvernoux/micropython,blazewicz/micropython,pramasoul/micropython,pramasoul/micropython,swegener/micropython,swegener/micropython,pozetroninc/micropython,adafruit/micropython,adafruit/circuitpython,ryannathans/micropython,trezor/micropython,infinnovation/micropython,pfalcon/micropython,MrSurly/micropython,pfalcon/micropython,kerneltask/micropython,bvernoux/micropython,MrSurly/micropython,selste/micropython,ryannathans/micropython,tobbad/micropython,henriknelson/micropython,pozetroninc/micropython,kerneltask/micropython,infinnovation/micropython,pfalcon/micropython,henriknelson/micropython,pramasoul/micropython,adafruit/micropython,adafruit/micropython,ryannathans/micropython,adafruit/micropython,kerneltask/micropython,ryannathans/micropython,kerneltask/micropython,bvernoux/micropython,tobbad/micropython,blazewicz/micropython,adafruit/circuitpython,dmazzella/micropython,pramasoul/micropython,dmazzella/micropython,pozetroninc/micropython,adafruit/micropython,swegener/micropython,pfalcon/micropython,ryannathans/micropython,adafruit/circuitpython,selste/micropython,MrSurly/micropython,blazewicz/micropython,selste/micropython,blazewicz/micropython,dmazzella/micropython,swegener/micropython,trezor/micropython,henriknelson/micropython,bvernoux/micropython,adafruit/circuitpython,tralamazza/micropython,trezor/micropython,tobbad/micropython,henriknelson/micropython,henriknelson/micropython,infinnovation/micropython,infinnovation/micropython,tralamazza/micropython,adafruit/circuitpython,pozetroninc/micropython,selste/micropython,trezor/micropython,adafruit/circuitpython,bvernoux/micropython,MrSurly/micropython