change noscript icon from button to span

fix Part 1 of #8403

test plan:
1. disable scripts on a page
2. click noscript icon
3. open browser console. you should not see any CSP errors.

app/renderer/components/navigation/urlBar.js

@@ -557,7 +557,7 @@ class UrlBar extends React.Component {
         !this.showNoScriptInfo
         ? null
         : <span className={css(styles.noScriptContainer)}>
-          <button
+          <span
             data-l10n-id='noScriptButton'
             data-test-id='noScriptButton'
             className={css(styles.noScriptButton)}