Fixing /logout command (#2908)

i18n/en.json

@@ -387,6 +387,10 @@
     "id": "api.command_logout.success_message",
     "translation": "Logging out..."
   },
+  {
+    "id": "api.command_logout.fail_message",
+    "translation": "Failed to log out"
+  },
   {
     "id": "api.command_me.desc",
     "translation": "Do an action"