iOS 7 upgrade without carrier SIM
Is it possible to upgrade my iPhone 5 from iOS 6.1.4 to 7.0.4 without getting any invalid sim problems? My phone is currently locked at T-Mobile UK and I don't have a spare nano sim card where I live now. After upgrading to 7.0.4 it will ask me to insert T-Mobile sim card to pass the activation. What to do?
iPhone 5, iOS 6.1.4