Google Maps, marker.png SSL error

Using SSL on my site and unfortunately I'm getting a mixed content warning that is coming from the marker.png file within the google maps plugin. I noticed that all the times it is linked to in the plugin with _agm.root_url + '/img/system/marker.png' it is sending http:// instead of https:// anyway to switch this to a generic root form such as //mydomainhere.com vs http:// ???