reboot path changed recently to /usr/sbin/reboot

See https://github.com/OpenELEC/OpenELEC.tv/commit/6bfa5b0ee4a7053ce7619f3384fcff845c5425e6
Bump version to 40
Update github URL
Merge pull request #9 from sethyx/master

reboot path changed recently to /usr/sbin/reboot