PushProx is using fqdn.get() which is deprecated

[insanity54]

fqdn.Get() is deprecated

https://github.com/Showmax/go-fqdn/blob/869ae776d5881666b8e89ff9f536176ef1736658/legacy.go#L16

yet PushProx uses this function

https://github.com/prometheus-community/PushProx/blob/e69c705ede1ca350467309a9ca076ecf703bfd43/cmd/client/main.go#L45C70-L45C74

The replacement method to use is fqdn.FqdnHostname()