Fix tests to work with user config site fr.wikt

Two wikibase test cases assumed that the config specified wiki has
a data repository.

One page test didnt specify a source for a Link( ), so it defaulted
to the config site, which in the case of wikt behaves differently
to the expectations of the test writer.

Change-Id: Ic8075275e52b9cbbf8a3d24164be7ab665b97ed0