[atlas] Minor change to Atlas anchor DNS resolver configuration

Dear colleagues, Each RIPE Atlas anchor runs a DNS resolver. This resolver is configured as the primary resolver for the anchor, with the following directive at the top of the resolver configuration (/etc/resolv.conf): nameserver 127.0.0.1 For ease of configuration management, we are changing this directive to: nameserver ::1 This change will not affect DNS resolution on the anchors in any way. However, any measurement that does DNS lookups using the anchor's primary resolver will contain "::1" instead of "127.0.0.1" in "src_addr" field of results. If you're using any code to parse such results, and specifically looking for "127.0.0.1", you'll need to adjust your code to also look for "::1". Regards, Anand Buddhdev RIPE NCC