Hi!
If it was there it was because you had overidden them..
For a normal configuration they are supposed to be empty..
Unless you need them to be different from the default, clear them..
At least that's what is supposed to be the reason, mine where also set there and I don't remember ever setting them but Rob is a FreePBX developer and said they should only be filled in if you need something different from the default...
Have a nice day!
Nick