Fix missing TD_AGENT_{USER,GROUP}=root change.
Fix missing TD_AGENT_{USER,GROUP}=root change.

I missed this (for deb, rpm was ok) during the preceding merge.

iantalarico/google-fluentd,GoogleCloudPlatform/google-fluentd,GoogleCloudPlatform/google-fluentd,iantalarico/google-fluentd,GoogleCloudPlatform/google-fluentd,iantalarico/google-fluentd