Fix mass-deletion of DHCP leases

[DL6ER]

What does this implement/fix?

See title. Running parseInt("192.168.1.2", 10) does not result in a meaningful IP address. There is no room for exploiting anything here so we can use the input without sanitation. This bug has been reported on Discourse.

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Related issue or feature (if applicable): N/A

Pull request in docs with documentation (if applicable): N/A

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[yubiuser]

You have too many PRs...
#2792

[DL6ER]

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