Fix typo in EC2 SD docs (#8210)

Signed-off-by: George Brighton <george@gebn.co.uk>

docs/configuration/configuration.md

@@ -662,7 +662,7 @@ The following meta labels are available on targets during [relabeling](#relabel_
 * `__meta_ec2_instance_lifecycle`: the lifecycle of the EC2 instance, set only for 'spot' or 'scheduled' instances, absent otherwise
 * `__meta_ec2_instance_state`: the state of the EC2 instance
 * `__meta_ec2_instance_type`: the type of the EC2 instance
-* `__meta_ec2_ipv6_addresses`: comma seperated list of IPv6 addresses for the all the network interfaces of the instance, if available
+* `__meta_ec2_ipv6_addresses`: comma seperated list of IPv6 addresses assigned to the instance's network interfaces, if present
 * `__meta_ec2_owner_id`: the ID of the AWS account that owns the EC2 instance
 * `__meta_ec2_platform`: the Operating System platform, set to 'windows' on Windows servers, absent otherwise
 * `__meta_ec2_primary_subnet_id`: the subnet ID of the primary network interface, if available