Wi-Fi settings stays grayed out in iphone 4S with ios 8.1.2

I own an Iphone 4S, 16 GB. I've just updated to ios 8.1.2. Since I updated to ios 8 Wi-Fi settings began to fail, becoming grayed out. I have restart network settings several times and the problem stays the same. I have also restart the iphone and it didn't work. The Wi-Fi settings stays grayed out. I can't use Wi-Fi network anymore since.

This is an image:

I would be very grateful to any help

Thanks a lot