Replace lightning_settle_delay with enable_htlc_settle (asyncio.Event)

electrum/lnworker.py

@@ -385,6 +385,9 @@ class LNWallet(LNWorker):
         self.sweep_address = wallet.get_receiving_address()
         self.lock = threading.RLock()
         self.logs = defaultdict(list)  # type: Dict[str, List[PaymentAttemptLog]]  # key is RHASH
+        # used in tests
+        self.enable_htlc_settle = asyncio.Event()
+        self.enable_htlc_settle.set()
 
         # note: accessing channels (besides simple lookup) needs self.lock!
         self.channels = {}