Update conditional presence validation syntax
Update conditional presence validation syntax

The previous syntax no longer works. The new syntax requires that the valid URI
validation check be done separately.

YOTOV-LIMITED/whitehall,alphagov/whitehall,robinwhittleton/whitehall,askl56/whitehall,robinwhittleton/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,askl56/whitehall,alphagov/whitehall,hotvulcan/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,robinwhittleton/whitehall,ggoral/whitehall,alphagov/whitehall,alphagov/whitehall,YOTOV-LIMITED/whitehall,askl56/whitehall,askl56/whitehall,ggoral/whitehall,ggoral/whitehall,robinwhittleton/whitehall,hotvulcan/whitehall,ggoral/whitehall