File _servicedata of Package libsecp256k1

<servicedata>
  <service name="tar_scm">
    <param name="url">https://github.com/bitcoin-core/secp256k1.git</param>
    <param name="changesrevision">20a209f11c0b688dae97ad5d2a515d00022d7799</param>
  </service>
</servicedata>