remove unecessary line

Signed-off-by: Arthur Lu <learthurgo@gmail.com>

scripts/config.js

@@ -340,8 +340,6 @@ async function handleDiskAdd () {
 	let dialog = document.createElement("dialog-form");
 	document.body.append(dialog);
 	
-	let diskImage = config.data[this.dataset.disk];
-
 	dialog.header = `Create A New Disk`;
 
 	let options = "";