Updated document as per code change.

[alamzeeshan]

Updated document as per this change : #15235

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[elasticmachine]

Can one of the admins verify this patch?

[clintongormley]

Hi @alamzeeshan

Thanks for the PR. Please could I ask you to sign the CLA so that I can merge it in?
http://www.elasticsearch.org/contributor-agreement/

[alamzeeshan]

HI @clintongormley , I have signed the CLA

[clintongormley]

thanks @alamzeeshan - merged