Following on from a previous fix for the same problem made in
3a431fba50c96cc47d8273a6934e200993197b14.
Fixes issue #8052.
Signed-off-by: Damien George <damien@micropython.org>
To match network_lan.c and network_ppp.c, and make it clear what code is
specifically for WLAN support.
Also provide a configuration option MICROPY_PY_NETWORK_WLAN which can be
used to fully disable network.WLAN (it's enabled by default).
Signed-off-by: Damien George <damien@micropython.org>