viewing frontpage over HTTPS gives the red ssl bar

if your observium instance is setup to be served over HTTPS then on the homepage you dont get the green bar/https or you get warnings about mixed/insecure content depending on your browser

this is due to 2 references in the maps JS for images that are called explicitly via HTTP, i have attached a patch that changes these to be protocol agnostic as they can be also viewed via HTTPS

this restores the green bar at least for the home page - rest of observium is yet to be checked for https support