Add trailing slash to example

Author: swazynski

frontend/js/i18n/messages.json

@@ -132,7 +132,7 @@
       "access-list": "Access List",
       "allow-websocket-upgrade": "Websockets Support",
       "ignore-invalid-upstream-ssl": "Ignore Invalid SSL",
-      "custom-forward-host-help": "Add a path for sub-folder forwarding.\nExample: 203.0.113.25/path",
+      "custom-forward-host-help": "Add a path for sub-folder forwarding.\nExample: 203.0.113.25/path/",
       "search": "Search Host…"
     },
     "redirection-hosts": {