build(dev-deps): update vue-router to 3.4.9

The parameter encoding is now fixed as of:
vuejs/vue-router#3350

Author: ttshivers

package-lock.json

@@ -57,7 +57,7 @@
     "vue": "^2.6.12",
     "vue-chat-scroll": "^1.4.0",
     "vue-cli-plugin-vuetify": "^2.0.7",
-    "vue-router": "3.4.5",
+    "vue-router": "^3.4.9",
     "vue-template-compiler": "^2.6.12",
     "vuetify": "^2.3.16",
     "vuetify-loader": "^1.6.0",