This is an old issue that many people have had because the phone expects to read the phone number from the SIM but many do not have it set for various reasons (number port etc.).
Easiest fix is to borrow a dumb / feature phone or an iPhone and set your number on your SIM using that phone's functions to do so.
Your N4 will then read the number correctly.
I used my girlfriend's iPhone to set my number after a number port - takes about 5 mins and it's a permanent fix (for that number and SIM combination obviously).