Allow a content type only once (Only One) (7.x-1.9) - en to ca translation catalogue (6 entries)

en: Content
ca: Contingut

en: Add content
ca: Afegeix contingut

en: About
ca: Detalls

en: Not applicable
ca: No aplicable

en: Uses
ca: Usos

en: Not specified
ca: Sense especificar
