[core] taskmanager: removed the ability to stop a mongo operation#5788

ArtursKadikis merged 2 commits intonextCountly/countly-server:nextfrom

SER-1991-ss-taskmanager-uses-comment-field-for-identifying-operationCountly/countly-server:SER-1991-ss-taskmanager-uses-comment-field-for-identifying-operationCopy head branch name to clipboard