Backport PR #379 on branch 3.x (Users item toolbar)#440

davidbrochart merged 1 commit intojupyterlab:3.xjupyterlab/jupyter-collaboration:3.xfrom

meeseeksmachine:auto-backport-of-pr-379-on-3.xmeeseeksmachine/jupyter-collaboration:auto-backport-of-pr-379-on-3.xCopy head branch name to clipboard