noNullPoints not working

[rev138]

Hi,

I'm using graphite-api 1.1.3 from EPEL. It appears the "noNullPoints" parameter isn't working. If I make a request like the following, there are still lots of 'null' datapoints in the response.

https://example.com/render?target=collectd.hostname.df-*.df_complex-free&format=json&noNullPoints=true

[{"target": "collectd.hostname.df-boot.df_complex-free", "datapoints": [[null, 1568297880], [null, 1568297940], [null, 1568298000], [null, 1568298060], [null, 1568298120], [null, 1568298180], [null, 1568298240], [null, 1568298300], [null, 1568298360], [null, 1568298420], [null, 1568298480], [null, 1568298540], [null, 1568298600], [null, 1568298660], [null, 1568298720], [null, 1568298780], [null, 1568298840], [null, 1568298900], [null, 1568298960], [null, 1568299020], [null, 1568299080], [null, 1568299140], [null, 1568299200], [null, 1568299260], [null, 1568299320], [null, 1568299380], [null, 1568299440], [null, 1568299500], [null, 1568299560], [null, 1568299620], [null, 1568299680], [null, 1568299740], [null, 1568299800], [null, 1568299860], [null, 1568299920], [null, 
...

Please advise.