Help - Changing Page Extension

Whenever I upgrade to a new version, I have to edit

fn_define('SEO_FILENAME_EXTENSION', '.htm');
changing the end from .html to just .htm
I just upgraded to the latest version and changed the file mentioned above,
I deleted the /var/cache
but still my pages want to end in .html
My store is closed right now as I do not want to open it and have Google index all my pages with a html extension. (That would be all brand new pages)
Any ideas on if there is anything else that I could try?
I've put in a help ticket but they won't even see it today due to time zone differences.

The fix was to change from php7.0 to php7.2.

Tried going to php7.3 but that gave errors, so I backed down to php7.2.

I had been on on cs-cart v4.7.2 and now am on 4.9.3SP1.

This also fixed other minor inconveniences I ran into on other installations that were already on later versions of cs-cart.

Just wanted to give an update to close this out. Just needed to update php.

Thank you for letting us know it