Update dependency url-loader to v4

Author: renovate-bot

package-lock.json

@@ -53,7 +53,7 @@
     "source-map-loader": "0.2.4",
     "style-loader": "1.2.1",
     "typescript": "3.9.6",
-    "url-loader": "2.3.0",
+    "url-loader": "4.1.0",
     "webpack": "4.43.0",
     "webpack-cli": "3.3.12",
     "webpack-dev-server": "3.11.0",