en to hr translation catalogue (3 entries)

note: i18n: ectx: property (title), widget (QGroupBox, groupBox_2)
en: Preview
hr: Pregled

note: i18n: ectx: property (text), widget (QLabel, labelAuthor)
en: Author:
hr: Autor:

note: i18n: ectx: property (text), widget (QLabel, labelContact)
en: Contact:
hr: Kontakt:
