Location Services empty option

Hello everyone ! Today I saw this in the Location Services menu under Settings. And I can't really tell what option is missing in the empty space, near the ON toggle switcher. I looked up for any app that requested my location so I could find it, but it didn't work. I have to mention that I have just restored my iPhone 4, and the only apps I installed are the following: Twitter, Find my iPhone, Find my Friends, iBooks and Dropbox. So, if you have an idea about getting this error fixed, please reply. Have a nice day !