All of the Auctiva links are secured, and have been updated even for GTC listings (where the listings meets eBay's revise criteria, in some cases the eBay does not allow Auctiva to revise an active listing for a number of different reasons).
In quickly look at one of your listings (https://www.ebay.com/itm/162725733300), it looks like you were at one point using a tool called "Parcel2Go" which has inserted not only an insecure image (http://www.parcel2go.com/images/p2go_v_small_logo.jpg), but also an offsite link (http://www.parcel2go.com/?referrer=auctioninsert) which is also against ebay policy. See image below:

You can use the Auctiva bulk revise tool, and revise your description to replace the text of the image and link "Parcel2Go" has inserted into your listigns, with and empty space (i.e. blank or nothing)