Fix availability graphs to 100%

[laf]

Please give a short description what your pull request is for

Fixes: https://community.librenms.org/t/missing-availability-graphs/21316

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[librenms-bot]

This pull request has been mentioned on LibreNMS Community. There might be relevant details there:

https://community.librenms.org/t/missing-availability-graphs/21316/3

[librenms-bot]

This pull request has been mentioned on LibreNMS Community. There might be relevant details there:

https://community.librenms.org/t/23-5-0-changelog/21481/1