Disallow empty hardware key xibosignage/xibo#2416
Disallow empty hardware key xibosignage/xibo#2416

(cherry picked from commit 66332367a2643d05a39fcc0285106a557378b59f)

xibosignage/xibo-cms,xibosignage/xibo-cms,alexharrington/xibo-cms,xibosignage/xibo-cms,dasgarner/xibo-cms,dasgarner/xibo-cms,alexharrington/xibo-cms,xibosignage/xibo-cms,alexharrington/xibo-cms,dasgarner/xibo-cms,xibosignage/xibo-cms,alexharrington/xibo-cms,dasgarner/xibo-cms,dasgarner/xibo-cms,xibosignage/xibo-cms,dasgarner/xibo-cms,alexharrington/xibo-cms