Fix invalid <nav ... role="tablist"> in docs.

build/vnu-jar.js

@@ -27,7 +27,6 @@ childProcess.exec('java -version', (error, stdout, stderr) => {
     // Firefox's non-standard autocomplete behavior - see https://bugzilla.mozilla.org/show_bug.cgi?id=654072
     'Attribute “autocomplete” is only allowed when the input type is.*',
     'Attribute “autocomplete” not allowed on element “button” at this point.',
-    'Bad value “tablist” for attribute “role” on element “nav”.',
     // We use holder.js with `data-src` and no `src` to avoid 404 errors;
     // we could work around this, but I'm not sure it's worth it.
     'Element “img” is missing required attribute “src”.',