adding stitch logo with a lower case 's'. i.e. stitch.png instead of Stitch.png

Merged username-removed-1527837 requested to merge thanadams/www-gitlab-com:stitchlogo into master

@ernstvn changing the "Stitch.png" logo to "stitch.png" so the image will show in the applications page. Sorry to have to do this once more. Thanks!