fix(lb): remove irrelevant troubleshooting

Author: RoRoJ

pages/load-balancer/troubleshooting/configuration.mdx

@@ -40,20 +40,6 @@ Either:
 - [Resize](/load-balancer/how-to/resize-lb/) your Load Balancer to a type that is compatible with multi-cloud backend servers, or
 - Use only Scaleway resources as backend servers for your Load Balancer
 
-## When adding a backend server via its private IP address, I get the message: IP doesn't exist
-
-You may be trying to [add a backend server](/load-balancer/how-to/create-frontends-backends/#configuring-traffic-management) to your Load Balancer's backend using the server's private IP address, and experience an error message saying that the IP doesn't exist.
-
-### Cause
-
-You are entering an incorrect IP address for your resource, or using private IP address that is outside the standard range for private networks.
-    
-### Solution
-
-- Check that you are entering the correct [private IP address](/vpc/how-to/attach-resources-to-pn/#how-to-view-the-resources-ip-address) for your resource, and that it is attached to the same Private Network as the Load Balancer.
-- Verify that you are using a private IP address that is within the standard ranges used for private networks as described in [RFC1918](https://en.wikipedia.org/wiki/Private_network#Private_IPv4_addresses). Only IP addresses from within one of these ranges are supported by Scaleway Load Balancer.
-
-
 ## My Load Balancer's Elastic Metal backend servers added via private IPs are all down
 
 You may add Elastic Metal backend servers to your Load Balancer using their private IP address, and find they are marked as `DOWN` as soon as you add them. You are unable to work out why they are failing their health checks.