message: test: use f-strings in feature_cltv.py
diff: @@ -135,7 +135,7 @@ class BIP65Test(BitcoinTestFramework):
  block.nVersion = 3
  block.solve()
  - with self.nodes[0].assert_debug_log(expected_msgs=['{}, bad-version(0x00000003)'.format(block.hash)]):
  + with self.nodes[0].assert_debug_log(expected_msgs=[f'{block.hash}, bad-version(0x00000003)']):
  peer.send_and_ping(msg_block(block))
  assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
  peer.sync_with_ping()
  @@ -173,8 +173,7 @@ class BIP65Test(BitcoinTestFramework):
  block.hashMerkleRoot = block.calc_merkle_root()
  block.solve()
  - with self.nodes[0].assert_debug_log(expected_msgs=['CheckInputScripts on {} failed with {}'.format(
  - block.vtx[-1].hash, expected_cltv_reject_reason)]):
  + with self.nodes[0].assert_debug_log(expected_msgs=[f'CheckInputScripts on {block.vtx[-1].hash} failed with {expected_cltv_reject_reason}']):
  peer.send_and_ping(msg_block(block))
  assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
  peer.sync_with_ping()
  