Describe the bug
I run puma in refork mode, but when I run pumactl refork I just get:

Invalid request command: refork

refork does appear in the list of available commands when I run pumactl --help. Sending SIGURG to the main puma process works fine. Other pumactl commands, such as gc and stats, work fine.

Desktop (please complete the following information):

• OS: Ubuntu Linux
• Puma Version 5.5.0