Bug#747563: Missing dependency on gnome-online-miners

Add dependency on gnome-online-miners closes #734187, but the package gnome-online-miners does not exist, is imposible install gnome-documents 3.12.1-1 -- Saludos, Roberto De Oliveira

Bug#747563: Missing dependency on gnome-online-miners

Package: gnome-documents Version: 3.12.0-1 Severity: serious Starting with gnome-documents 3.10, the miners were split out into a separate module called gnome-online-miners [0]. We need to package this module before moving gnome-documents 3.12 to unstable. [0] https://bugzilla.gnome.org/show_bu