fixed a typo

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/trac352@3289 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/python/isc/utils/serve_mixin.py

@@ -38,7 +38,7 @@ class ServeMixIn:
     def serve_forever(self, poll_interval=None):
         ''' Override the serve_forever([poll_interval]) in class
         socketserver.TCPServer by using the socketpair to wake up
-        instead of pulling.
+        instead of polling.
           Note, parameter 'poll_interval' is just used to keep the
         interface, it's never used in this function.
         '''