Update dependency uglify-js to v3.19.0

Author: renovate[bot]

assets/jquery/package.json

@@ -63,7 +63,7 @@
     "sizzle": "2.3.6",
     "strip-json-comments": "2.0.1",
     "testswarm": "1.1.2",
-    "uglify-js": "3.4.7"
+    "uglify-js": "3.19.0"
   },
   "scripts": {
     "build": "npm install && grunt",