In the CI dig sometimes produces warning/error comments when
communicating with the server, which produces problems when comparing
the outputs.
Here is an example of a dig output with a warning message which
is benign, because dig, after a retry, managed to query the server.
;; communications error to 10.53.0.3#7529: timed out
1.2.3.1
1.2.3.2
1.2.3.3
1.2.3.4
When comparing this to the expected output, which doesn't contain
the comment line (starting with double ';'), the outputs don't match.
Use grep inverse logic to strip the comments from the dig outputs.
65d9d90b55