Log the line when failing a PromQL test. (#4272)
Log the line when failing a PromQL test. (#4272)

Signed-off-by: Alin Sinpalean <ca82fdd1dd8d4beec0f5d75e77ad4be7ccc694a7@gmail.com>
Gouthamve/prometheus,alileza/prometheus,keegancsmith/prometheus,kangwoo/prometheus,kangwoo/prometheus,amorken/prometheus,prometheus/prometheus,amorken/prometheus,kangwoo/prometheus,kangwoo/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,keegancsmith/prometheus,prometheus/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,amorken/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,alileza/prometheus,Gouthamve/prometheus,keegancsmith/prometheus,alileza/prometheus,prometheus/prometheus,alileza/prometheus,amorken/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus