Update dependency react-hot-loader to v4.8.4

Author: renovate-bot

web/package-lock.json

@@ -14,7 +14,7 @@
     "ramda": "0.26.0",
     "react": "16.6.0",
     "react-dom": "16.6.0",
-    "react-hot-loader": "4.3.12",
+    "react-hot-loader": "4.8.4",
     "react-lowlight": "2.0.0",
     "react-router": "4.3.1",
     "react-router-dom": "4.3.1",