Fix curl args for data-urlencode
Fix curl args for data-urlencode

The curl argument `--data-urlencode` doesn't accept equal signs between
the arg and the value, but needs whitespace instead.

Signed-off-by: Clayton O'Neill <7833bf63e3b444bee2fe361e4dae2494a492a313@github.com>

Gouthamve/prometheus,keegancsmith/prometheus,kangwoo/prometheus,prometheus/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,prometheus/prometheus,prometheus/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,Gouthamve/prometheus,kangwoo/prometheus,alileza/prometheus,alileza/prometheus,kangwoo/prometheus,prometheus/prometheus,Gouthamve/prometheus,kangwoo/prometheus,prometheus/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,alileza/prometheus