Update dependency serve-favicon to v2.5.0 (#945)

Author: renovate[bot]

appengine/loopback/package.json

@@ -19,7 +19,7 @@
     "helmet": "3.15.0",
     "loopback-boot": "2.27.1",
     "loopback-component-explorer": "5.3.0",
-    "serve-favicon": "2.4.5",
+    "serve-favicon": "2.5.0",
     "strong-error-handler": "2.3.2",
     "loopback-datasource-juggler": "3.28.0",
     "loopback": "3.24.0"