registryctl logs http: Server closed as fatal during graceful shutdown

[rakshityadav1868]

Issue Title

registryctl logs http: Server closed as fatal during graceful shutdown

Description

Summary

registryctl logs a fatal error during normal graceful shutdown:

However, this is caused by http.ErrServerClosed, which is expected behavior when the HTTP server shuts down gracefully.

Current Behavior

In RegistryCtl.Start():

err = regCtl.ListenAndServe()
...
if err != nil { log.Fatal(err) }

ListenAndServe() returns http.ErrServerClosed after a successful shutdown, causing Harbor to incorrectly emit a fatal log.

Expected Behavior

Graceful shutdown should not produce fatal logs.

http.ErrServerClosed should be ignored explicitly.

Result

After applying the fix:

• graceful shutdown logs are clean
• no misleading fatal message appears
• shutdown behavior remains unchanged