Clarify that {a="b",a!="c"} is possible. (#4492)
Clarify that {a="b",a!="c"} is possible. (#4492)

Signed-off-by: Brian Brazil <aadf89994a343dc176a47081f0c0bbea26f0a345@robustperception.io>
kangwoo/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,kangwoo/prometheus,prometheus/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,prometheus/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,keegancsmith/prometheus,alileza/prometheus,prometheus/prometheus,kangwoo/prometheus,Gouthamve/prometheus,alileza/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,alileza/prometheus