feat: update cover

src/app/map/App.vue

@@ -89,7 +89,7 @@ import { ElLoading } from "element-plus";
 import linkIco from "@/assets/image/fire.ico";
 import { useUrlSearchParams } from "@vueuse/core";
 import emptyBG from "@/assets/image/empty__empty.png";
-import emptyCover from "@/assets/image/pic.jpg";
+import emptyCover from "@/assets/image/cover.png";
 
 import { changeThemeColor } from "./theme";
 const params = useUrlSearchParams("history");