persist channel db on disk. verify channel gossip sigs.

electrum/network.py

@@ -301,7 +301,7 @@ class Network(Logger):
 
         # lightning network
         self.lightning_nodes = {}
-        self.channel_db = lnrouter.ChannelDB()
+        self.channel_db = lnrouter.ChannelDB(self)
         self.path_finder = lnrouter.LNPathFinder(self.channel_db)
         self.lnwatcher = lnwatcher.LNWatcher(self)
 
@@ -1183,6 +1183,7 @@ class Network(Logger):
     def stop(self):
         assert self._loop_thread != threading.current_thread(), 'must not be called from network thread'
         fut = asyncio.run_coroutine_threadsafe(self._stop(full_shutdown=True), self.asyncio_loop)
+        self.channel_db.save_data()
         try:
             fut.result(timeout=2)
         except (asyncio.TimeoutError, asyncio.CancelledError): pass