add missing inclusion
Merge pull request #834 from ontohub/330-file_extensions_in_database

330 file extensions in database
fix maintenance mode for git

Ontohub::Application is not available in git mode,
as we do not preload the whole rails environment.
To get to related settings one needs the assume this:

Ontohub::Application.config ~= Settings.
Merge branch '835-fix_ssh_again' into develop