Added missing sys.exit call

git-svn-id: http://svn.zope.org/repos/main/zc.buildout/trunk@122990 62d5b8a3-27da-0310-9561-8e5933582275

zc.recipe.egg_/src/zc/recipe/egg/selecting-python.txt

@@ -91,7 +91,7 @@ And the generated scripts invoke Python 2.5:
     import eggrecipedemo
     <BLANKLINE>
     if __name__ == '__main__':
-        eggrecipedemo.main()
+        sys.exit(eggrecipedemo.main())
 
     >>> if sys.platform == 'win32':
     ...     f = open(os.path.join(sample_buildout, 'bin', 'py-demo-script.py'))