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.
@@ -236,7 +236,7 @@ The following example returns all series that match either of the selectors
`up` or `process_start_time_seconds{job="prometheus"}`:
```json
-$ curl -g 'http://localhost:9090/api/v1/series?' --data-urlencode='match[]=up' --data-urlencode='match[]=process_start_time_seconds{job="prometheus"}'
+$ curl -g 'http://localhost:9090/api/v1/series?' --data-urlencode 'match[]=up' --data-urlencode 'match[]=process_start_time_seconds{job="prometheus"}'
{
"status" : "success",
"data" : [
