unix/main: Allow to build with MICROPY_DEBUG_PRINTERS == 0.
unix/main: Allow to build with MICROPY_DEBUG_PRINTERS == 0.

Change-Id: Id868d154adc9c8f865fef616b6a1d35e61eb9fe0

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython