update configure.ac to make sure we have libosmocore-0.3.9
update configure.ac to make sure we have libosmocore-0.3.9

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