Fixed footer display bug and theme options screen maintenance

【Contents of the fix】
■Fixed a bug that some of the adjacent custom menus are not displayed correctly when the footer logo is not set (when the site title is displayed).
■Removed the unnecessary “Save Settings” button at the bottom of the Custom CSS Settings field.
■Added a reference link in the Facebook OGP settings section.

The following files have been modified for this update.
【Corrected files】
admin/theme-options.php
languages/en.mo
languages/en.po
style.css
style_pc.css

For more information, please visit the download site for purchasers of LUXE (tcd022).