Someone else may have a better idea, but personally this is what I think should be done. If you are very concerned about it you can get a roll of rubberized self adhesive tape, I think it's called Eternabond, or something like that. Clean the area around the scrape with soap & water, and let it get completely dry, then apply the tape, and use a roller, or something to roll it down to get rid of any bubbles, and to make sure it sticks good to the roof material. Then get some Dicor self-leveling caulk and clean the scrape and an area around it, like I mentioned above, then apply it around the edge of the tape. If it's minor, and you are just concerned it "may" be an issue in the future, you could clean the area like above, then use some of the Dicor self-leveling caulk and apply it in the area of the scrape, covering not only the scrape, but a portion of the area around it. Hope this helps!