[wiki] Export file invalid
Importing a wiki export file misses some wikis, even if they appear in the export file.
Reported by Caranistar. See https://zotlabs.org/display/b64.aHR0cHM6Ly96b3RsYWJzLm9yZy9pdGVtLzcyYjQ4YTkyLTc0N2QtNDBiMC1hZjllLTFhNzUyZTJmYWMwZQ