Fix link to Rézo Metz website
The link to https://rezometz.org in the about page was broken by !572 (merged):
<a href="https://Rézo Metz.org/">Rézo Metz</a>
The link to https://rezometz.org in the about page was broken by !572 (merged):
<a href="https://Rézo Metz.org/">Rézo Metz</a>