Fix glidein_status

[mambelli]

Describe the bug
An error (stack trace) occurs when invoking glidein_status in the Factory

$ glidein_status
WARNING: GSI authentication is enabled by your security configuration! GSI is no longer supported.
For details, see https://htcondor.org/news/plan-to-replace-gst-in-htcss/
Traceback (most recent call last):
  File "/usr/bin/glidein_status", line 415, in <module>
    main()
  File "/usr/bin/glidein_status", line 258, in main
    keys.sort(machine_cmp)
TypeError: sort() takes no positional arguments

To Reproduce
Invoke glidein_status in the Factory

Expected behavior
No stack trace

Screenshots
NA

Info (please complete the following information):
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• GlideinWMS version: 3.10.7
• Python version: 3.9
• OS version: Alma9
• HTCondor version: 23
• Priority: medium
• Stakeholders: Fermilab
• Components: factory

Additional context
NA