Allow optional trailing slash when using optional parameter
I found this way to achive this with Apache mod_rewrite enabled. Snippet of .htaccess
RewriteEngine On
# remove trailing slash
RewriteCond %{HTTPS} off
RewriteRule ^(.+[^/])/$ http://%{HTTP_HOST}/$1 [R=301,L]
RewriteCond %{HTTPS} on
RewriteRule ^(.+[^/])/$ https://%{HTTP_HOST}/$1 [R=301,L]