Update dependency vue-i18n to v9.1.9

Author: renovate-bot

app/package.json

@@ -16,7 +16,7 @@
     "parse-torrent": "9.1.3",
     "register-service-worker": "1.7.2",
     "vue": "2.6.12",
-    "vue-i18n": "9.1.4",
+    "vue-i18n": "9.1.9",
     "vue-plyr": "7.0.0",
     "vue-promised": "2.0.3",
     "vue-router": "3.5.1",