Fix inifnite loop bug

The wire request may fail due to choking or wire closed. This results in an infinite loop.

lib/torrent.js

@@ -1545,6 +1545,10 @@ class Torrent extends EventEmitter {
       })
     })
 
+    // the wire may be choking or closed
+    if (numRequests === wire.requests.length)
+      return false
+
     function onUpdateTick () {
       process.nextTick(() => { self._update() })
     }