remove duplicate e-mail introduce during rebase.
removing to resolve conflict

Conflicts:
	components/tools/OmeroWeb/omeroweb/webgateway/views.py
Merge remote-tracking branch 'origin/develop' into simplejson_upgrade

Conflicts:
	components/tools/OmeroWeb/omeroweb/webgateway/views.py
Join session and re-activate re.
Replace reconnect by joinSession
Fix import exception window sizing.
Correct whitespace.
Fix NPE if no archived returned.
Remove import.
Fix units if value is 0.0
Make sure that we always at least one group available for a user.
Do not allow to download plates
Check that the correct component is visible.
Add DBUserCheck to create a Roles object from the DB (See #11813)

By default the strings "user", "guest", "root", and "system" are
used to look up the IDs. By setting omero.roles.user.guest etc.
in config.xml, other strings can be used, but this is NOT suggested.
Add dbUserCheck to background processes
Use EvaluatorFilter to exclude some DEBUG logging from Blitz.log
Check if the namespace is the tag set ns (see #11382)
Remove tabs and spaces.
Clean up.
Lay out the component after adding to main view. (see #11833)