stm32/modnetwork: Remove redundant call to nimble_poll in lwip poll.
stm32/modnetwork: Remove redundant call to nimble_poll in lwip poll.

The bluetooth stack has its own dedicated polling function, see
mod_bluetooth_nimble_poll_wrapper().

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