reverted to the old favicon path (#24559)

api/v4/html/ssr_template.hbs

@@ -6,7 +6,7 @@
   <title>Mattermost API Reference</title>
   <!-- needed for adaptive design -->
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <link rel="shortcut icon" href="./favicon.ico">
+  <link rel="shortcut icon" href="./static/favicon.ico">
   <style>
     body {
       padding: 0;