Remove duplication.
diff --git a/Lib/sched.py b/Lib/sched.py
index f6a699c..a119892 100644
--- a/Lib/sched.py
+++ b/Lib/sched.py
@@ -94,7 +94,7 @@
         restarted.
 
         It is legal for both the delay function and the action
-        function to to modify the queue or to raise an exception;
+        function to modify the queue or to raise an exception;
         exceptions are not caught but the scheduler's state remains
         well-defined so run() may be called again.