fix: use isPrivate to detect private multiaddrs

[achingbrain]

To prevent throwing when non-thin waist addresses are encountered, use isPrivate instead of converting the multiaddr to a node address.

Change checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if necessary (this includes comments as well)
• I have added tests that prove my fix is effective or that my feature works