s.src = "https://mc.yandex.ru/metrika/tag.js";

s.src = "/path/to/js/yandex_metrika_tag.js";

<IfModule mod_headers.c>
    Header set Cache-Control "max-age=86400"
    Header set Pragma "max-age=86400"
    Header set Expires 0
</IfModule>

<FilesMatch ".(html?|txt|css|js|php|pl)$">
    SetOutputFilter DEFLATE
</FilesMatch>