Fixed JS conditional logic issue caused by nested repeater in flexible content

Signed-off-by: Elliot Condon <e@elliotcondon.com>
Adding to change log

Signed-off-by: Elliot Condon <e@elliotcondon.com>
Fixed bug with get_sub_field function

Signed-off-by: Elliot Condon <e@elliotcondon.com>