Revoking permission does not remove project from revoked user's mscolab project window

[Tanish Grover]

In mscolab/server.py revoke_permission function does not emit any socket event to remove the project.

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[Reimar Bauer]

fixes issue #538, revoke permission not firing socket event

→ <<cset 99af60d99d23>>

[Reimar Bauer]

Merged in tanish19/mss/issue538 (pull request #797)

fixes issue #538, revoke permission not firing socket event

→ <<cset e4e8358a866a>>