Bug 1599305: Set users 'grouproles' to only contain undeleted groups

And also update the current user's group roles on group deletion

behatnotneeded

Change-Id: Id32ea6b0ba95a4057c1a84e860aa2ded3879f8b0
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>
(cherry picked from commit 8b93bf61)