fixed incompatibility with older versions of Twisted

diff --git a/p2pool/util/deferral.py b/p2pool/util/deferral.py
index 71fe633..0601d39 100644 (file)
--- a/p2pool/util/deferral.py
+++ b/p2pool/util/deferral.py
@@ -103,7 +103,10 @@ class GenericDeferrer(object):
         def cancel(df):
             df, timer = self.map.pop(id)
             timer.cancel()
-        df = defer.Deferred(cancel)
+        try:
+            df = defer.Deferred(cancel)
+        except TypeError:
+            df = defer.Deferred() # handle older versions of Twisted
         def timeout():
             self.map.pop(id)
             df.errback(failure.Failure(defer.TimeoutError('in GenericDeferrer')))