Fix addon 'nuxeo-wopi' preventing Nuxeo Dev Tools to connect to Nuxeo server

When addon nuxeo-wopi, the Nuxeo Dev Tools is unable to connect to the Nuxeo server.

How to reproduce:

• install the nuxeo-wopi addon in a LTS 2021 Nuxeo instance
• start the Nuxeo instance
• in a browser, click on the *Nuxeo Dev Tools

Expected result: Nuxeo Dev Tools menu opens, and the Hot reload button and the JSON export icon appear
Actual result: Nuxeo Dev Tools menu opens, and the Hot reload button and the JSON export icon don't appear, and the message No Studio package found! appears in the menu

Stack traces are logged in the server.log file when the Nuxeo Dev Tools tries to connect to the Nuxeo instance, see attached file nuxeo-dev-tools-server.log.