Don't re-create record if IP already matches record

[skoobasteeve]

I know there's another PR open with more comprehensive changes, but this is a small quality-of-life improvement I made in my own environment. It always scared me (irrationally) that records were being deleted and replaced every time the script ran, so I added a simple check to compare the myIP variable to the record content and only delete the record if the values don't match.

Thanks for providing this script and your stellar registrar services! Let me know if you have questions or concerns.