Validate urls in modal
Validate urls in modal

- Urls added via a model are stored in the DB and need to be validated

Credits: Abdel Adim Oisif

JohnONolan/Ghost-Admin,TryGhost/Ghost-Admin,kevinansfield/Ghost-Admin,kevinansfield/Ghost-Admin,JohnONolan/Ghost-Admin,acburdine/Ghost-Admin,dbalders/Ghost-Admin,airycanon/Ghost-Admin,TryGhost/Ghost-Admin,dbalders/Ghost-Admin,acburdine/Ghost-Admin,airycanon/Ghost-Admin