fix Mozilla typo (#8395)

templates/unsupported_browser.html

@@ -151,7 +151,7 @@
           </li>
           <li>
             <a href="https://www.mozilla.org/en-US/firefox/new/" target="_blank" rel="noopener noreferrer">
-              <span>Mozzilla Firefox 52+</span>
+              <span>Mozilla Firefox 52+</span>
             </a>
           </li>
           <li>