tests/pyb: Update UART expected output now that default timeout is 0.
tests/pyb: Update UART expected output now that default timeout is 0.

Follow up to commit 34942d0a72980173eca51b201f271f67bcae46b5

MrSurly/micropython,MrSurly/micropython,pozetroninc/micropython,trezor/micropython,henriknelson/micropython,bvernoux/micropython,henriknelson/micropython,henriknelson/micropython,bvernoux/micropython,pozetroninc/micropython,adafruit/circuitpython,trezor/micropython,tobbad/micropython,pfalcon/micropython,selste/micropython,adafruit/circuitpython,pozetroninc/micropython,adafruit/circuitpython,kerneltask/micropython,adafruit/circuitpython,selste/micropython,MrSurly/micropython,bvernoux/micropython,trezor/micropython,kerneltask/micropython,henriknelson/micropython,pramasoul/micropython,adafruit/circuitpython,kerneltask/micropython,kerneltask/micropython,tobbad/micropython,pfalcon/micropython,trezor/micropython,henriknelson/micropython,MrSurly/micropython,bvernoux/micropython,tobbad/micropython,selste/micropython,bvernoux/micropython,pramasoul/micropython,pfalcon/micropython,pozetroninc/micropython,selste/micropython,MrSurly/micropython,selste/micropython,pramasoul/micropython,tobbad/micropython,trezor/micropython,adafruit/circuitpython,kerneltask/micropython,pramasoul/micropython,tobbad/micropython,pfalcon/micropython,pramasoul/micropython,pfalcon/micropython,pozetroninc/micropython