text: Title: Server logs flooded with Skipping invalid IP
  Body: Originally post on project https://github.com/k3s-io/k3s/issues/3255
  
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  **Environmental Info:**
  K3s Version: v1.21.0+k3s1
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  Node(s) CPU architecture, OS, and Version: Linux 4.19.0-16-cloud-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64 
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  Cluster Configuration: 1 server & 3 agents
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  **Describe the bug:**
  I use an external cloud controller manager to manage load balancing and services exposition. But on my services spec, I have no ```status.loadBalancer.ingress.IP``` field but  a ```status.loadBalancer.ingress.hostname``` instead. Everything works fine but server logs are flooded with entries like ```utils.go:288] Skipping invalid IP:```
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  **Steps To Reproduce:**
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  - Installed K3s: 
  - Use an external CCM which only  provide a hostname to expose service 
  
  **Expected behavior:**
  No more logs like ```utils.go:288] Skipping invalid IP:```
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  **Actual behavior:**
  Server logs are flooded with entries like ```utils.go:288] Skipping invalid IP:```
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  **Additional context / logs:**
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  Should it be a good idea to test consistency of IP here : https://github.com/kubernetes/kubernetes/blob/f235adc4d271c30c4e3b32f48196ae812a6c7100/pkg/proxy/service.go#L204 or here ? https://github.com/kubernetes/kubernetes/blob/f235adc4d271c30c4e3b32f48196ae812a6c7100/pkg/proxy/util/utils.go#L279