empty repozo option for plone.recipe.zeoserver doesn't behave like described in the documentation

[Vincent Fretin]

The documentation of plone.recipe.zeoserver says:

repozo
    The path to the repozo.py backup script. A wrapper for this will be generated in bin/repozo, which sets up the appropriate environment for running this. Defaults to using the repozo script from the ZODB3 egg. Set this to an empty value if you do not want this script to be generated.

If you use "repozo =", bin/buildout will raise an exception:

 File "/home/vincentfretin/.buildout/eggs/plone.recipe.zeoserver-1.1b1-py2.6.egg/plone/recipe/zeoserver/__init__.py",
line 368, in install_scripts
   'Custom repozo script not found: %s' % repozo)
AssertionError: Custom repozo script not found:

"zeopack =" works fine, the script is not generated.