iOS8 Screen Orientation Change

My app formerly known as "SpyBot" (now "RocketBot") was submitted to the App Store a few weeks ago. Until the new iOS update, everything was working fine. Now, I have a huge problem, when the new iOS8 update kicked in, my app's default orientation changed to portrait. I thought it was little bug, so I waited for my update to be submitted to the App Store. My game was updated today, and I was shocked and furious when I saw that the orientation was portrait. I have no idea how this could have happened : I double checked the orientation settings on Xcode and Unity and everything seems to be correct.

How can I solve this problem ?