Fixed a display bug that occurs on iPhone

■【iPhone】Fixed a bug where the Hatena bookmark icon was not displayed on the share button of the fixed footer bar.

The following are the files that have been fixed for this update.

【Modified files】
assets/css/footer-bar.css
assets/css/footer-bar.min.css
inc/footer-bar.php
inc/update_notifier.php
inc/widgets/google_search.php
languages/ja.mo
languages/ja.po
style.css

【Added files】
assets/images/hatenabookmark-logomark.svg