test: replace (send_message + sync_with_ping) with send_and_ping

test/functional/p2p_leak_tx.py

@@ -39,8 +39,7 @@ class P2PLeakTxTest(BitcoinTestFramework):
             want_tx = msg_getdata()
             want_tx.inv.append(CInv(t=1, h=int(txid, 16)))
             inbound_peer.last_message.pop('notfound', None)
-            inbound_peer.send_message(want_tx)
-            inbound_peer.sync_with_ping()
+            inbound_peer.send_and_ping(want_tx)
 
             if inbound_peer.last_message.get('notfound'):
                 self.log.debug('tx {} was not yet announced to us.'.format(txid))