Since the parent commit, the ra_ResponseWindow will be chosen
automatically. Correspondingly, remove most ra_ResponseWindow options
from configuration files in the repository.
One problem in some mu=1 configs is that the ra_ResponseWindow=4 (10
slots), which might be overly restrictive if the L1 slot ahead is
somewhat close to 10 (e.g., 6), in which case we might not be always
able to allocate Msg2 in time.
A notable exception here is gnb-vnf.sa.band66.u0.25prb.nfapi.conf, in
which we still provide it (1) since it uses a non-standard configuration
of a ra_ResponseWindow longer than 10ms (see also issue #916 for more
information) and (2) as an example.
francescomani