add missing parentheses on formerly excluded doctest example

IPython/testing/plugin/test_example.txt

@@ -1,24 +1,24 b''
 =====================================
  Tests in example form - pure python
 =====================================
 
 This file contains doctest examples embedded as code blocks, using normal
 Python prompts.  See the accompanying file for similar examples using IPython
 prompts (you can't mix both types within one file). The following will be run
 as a test::
 
     >>> 1+1
     2
-    >>> print "hello"
+    >>> print ("hello")
     hello
 
 More than one example works::
 
     >>> s="Hello World"
 
     >>> s.upper()
     'HELLO WORLD'
 
 but you should note that the *entire* test file is considered to be a single
 test.  Individual code blocks that fail are printed separately as ``example
 failures``, but the whole file is still counted and reported as one test.