It's possible to configure Umbraco to remove the final trailing slash on the URL. If you want to do this, locate the 'umbracoSettings.config' file. This can be found in the 'webroot\config\' directory of your site.
Open this file and locate the 'addTrailingSlash' setting in the 'requestHandler' section of the file.

<requestHandler>
<addTrailingSlash>false</addTrailingSlash>
</requestHandler>

Then all you need to do is to change the addTrailingSlash value to 'false'. Don't forget to save your changes.