When I have the footer set to one of the preset images it is making an insecure call
http://www.lephenix.co.uk/wp-content/themes/enfold/images/background-images/ios-linen-light.png
How can I change this be secure
You just need to replace the http:// protocol with https:// – make sure that all urls on the option page (Enfold > Styling – background images) use https:// as protocol and i.e. replace
http://www.lephenix.co.uk/wp-content/themes/enfold/images/background-images/ios-linen-light.png
with
https://www.lephenix.co.uk/wp-content/themes/enfold/images/background-images/ios-linen-light.png