update osmo-bts to conform to L1 v2.4 API changes
update osmo-bts to conform to L1 v2.4 API changes

osmocom/osmo-bts,shimaore/osmo-bts,telenoobie/osmo-bts,telenoobie/osmo-bts,telenoobie/osmo-bts,shimaore/osmo-bts,tacooper/osmo-bts,osmocom/osmo-bts,tacooper/osmo-bts,geosphere/osmo-bts,geosphere/osmo-bts,geosphere/osmo-bts,geosphere/osmo-bts,shimaore/osmo-bts,shimaore/osmo-bts,osmocom/osmo-bts,telenoobie/osmo-bts