After the last commit, it is not possible to bind on separate interfaces
for F1-C and F1-U. In other words, it is for instance not possible to
have the F1-C on one subnet on one physical interface, and F1-U on
another subnet on another physical interface. This commit introduces a
second option MACRLCs.[0].local_n_address_f1u to allow to bind F1-U on
an alternative address; if it is not specified, the interface of F1-C is
reused.

The above only works for the DU; no corresponding option exists for the
CU. For the CU, use separate CU-CP and CU-UP.

Use it in the CI.