Issue:
In interwiki script a -graph option was introduced in Pywikibot 2.0 with rPWBC4d47c6f0, which was a backport from Pywikibot 1.0 (added there with rPWBOaa64036d). However, this option was never documented.
Other possible improvements
(not for good first task I guess)
- remove the config.interwiki_graph to clean up the config settings
- use ConfigParserBot instead to configure the options