Remove orientation lock on devices that do not handle it

[florentdescroix]

Hi, I have a desktop computer thus the orientation lock action is completely unecessary in my case.

To avoid having it, I modified the indicators/system.js file and put the whole block about orientation lock inside the following condition :
if (this._system._systemActions._orientationLockAction) {

I don't know if that's the actual good solution, because I can't tell if devices that have an orientation effectively have the this._system._systemActions._orientationLockAction property. But at least my system doesn't have it so it works :)

[johnmmcgee]

i also have this option showing up, but greyed out.