CentOS7のマイグレーションで「Actor vsftpd_config_read unexpectedly terminated with exit code: 1」

CentOS7→Almalinuxへ移行しようと移行ツールの「Elevate」でアップグレード前のチェック「leapp preupgrade」を実行したところエラー「Actor vsftpd_config_read unexpectedly terminated with exit code: 1」が出ました。

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Actor vsftpd_config_read unexpectedly terminated with exit code: 1 - Please check the above details
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Debug output written to /var/log/leapp/leapp-preupgrade.log

============================================================
                      REPORT OVERVIEW
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Reports summary:
    Errors:                      1
    Inhibitors:                  0
    HIGH severity reports:       0
    MEDIUM severity reports:     0
    LOW severity reports:        0
    INFO severity reports:       0

Before continuing, review the full report below for details about discovered problems and possible remediation instructions:
    A report has been generated at /var/log/leapp/leapp-report.txt
    A report has been generated at /var/log/leapp/leapp-report.json

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                   END OF REPORT OVERVIEW
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Answerfile has been generated at /var/log/leapp/answerfile

「/var/log/leapp/leapp-report.txt」には次のように出力されていました。

# cat /var/log/leapp/leapp-report.txt

Risk Factor: high (error)
Title: Actor vsftpd_config_read unexpectedly terminated with exit code: 1
Summary: Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/leapp/repository/actor_definition.py", line 75, in _do_run
    actor_instance.run(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/leapp/actors/__init__.py", line 316, in run
    self.process(*args)
  File "/usr/share/leapp-repository/repositories/system_upgrade/el7toel8/actors/vsftpdconfigread/actor.py", line 20, in process
    self.produce(vsftpdconfigread.get_vsftpd_facts())
  File "/usr/share/leapp-repository/repositories/system_upgrade/el7toel8/actors/vsftpdconfigread/libraries/vsftpdconfigread.py", line 41, in get_vsftpd_facts
    config_hash = utils.get_default_config_hash(read_func=read_func)
  File "/usr/share/leapp-repository/repositories/system_upgrade/el7toel8/libraries/vsftpdutils.py", line 49, in get_default_config_hash
    content = content.encode(encoding='utf-8')
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe3 in position 4992: ordinal not in range(128)

「/etc/vsftpd/vsftpd.conf」を確認してみたところ、コメントとして日本語（全角文字）が定義されていました。試しにこの行を削除して再度「leapp preupgrade」を実行したところこのエラーは解消しました。