Backup your .htaccess file.
In the .htaccess file add this to the top:
# Always use https for secure connections
# Replace 'www.example.com' with your domain name
# (as it appears on your SSL certificate)
RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.example.com/$1 [R=301,L]
Important! Replace www.example.com with your own domain name.
That should do it (worked for me)