5.3.1: tiny fixes

- fixed backdrop on press for "copy url" button in mobile "how to save?" popup
- added ability to disable cors via env file

package.json

@@ -1,7 +1,7 @@
 {
     "name": "cobalt",
     "description": "save what you love",
-    "version": "5.3",
+    "version": "5.3.1",
     "author": "wukko",
     "exports": "./src/cobalt.js",
     "type": "module",
@@ -26,7 +26,7 @@
         "cors": "^2.8.5",
         "dotenv": "^16.0.1",
         "esbuild": "^0.14.51",
-        "express": "^4.17.1",
+        "express": "^4.18.1",
         "express-rate-limit": "^6.3.0",
         "ffmpeg-static": "^5.1.0",
         "got": "^12.1.0",