Multiple bug fixes

【Contents of the fix】
■Fixed a bug in the fixed page “Plan Page” template.
(Bug in Plan Contents > Header Navigation Settings, the check change of “Show recommendation icons” is reflected in all other plan contents)
■TCD Theme > Header > Header Menu Settings > Dropdown Menu Item Specification Changes (Added checkbox to apply main color and sub color)
■Fixed a bug that the same URL for “Message in the bottom right corner” in TCD Theme > Top Page (for smartphone) > Header Content Settings is applied to both PC and smartphone.

The files that have been modified for this update are as follows

【Modified file】
admin/inc/header.php
admin/js/my_script.js
functions/head.php
functions/update_notifier.php
header.php
languages/ja.mo
languages/ja.po
style.css