(telnet.close): Extend the close method instead of overriding it.

pcl_expect/telnet.py

@@ -22,5 +22,6 @@ class telnet(pcl_expect.expectable):
         self.telnet.write(s)
 
     def close(self):
+        pcl_expect.expectable.close(self)
         self.telnet.close()