display_url: Don't duplicate public_url and local_url if they are the…

… same

jupyter_server/serverapp.py

@@ -2385,7 +2385,9 @@ def display_url(self) -> str:
         """Human readable string with URLs for interacting
         with the running Jupyter Server
         """
-        url = self.public_url + "\n    " + self.local_url
+        url = self.public_url
+        if self.public_url != self.local_url:
+            url = f"{url}\n    {self.local_url}"
         return url
 
     @property