Is that really needed?
I think it might have been on certain setups a long time ago (2 years or so?).
Its certainly a security compromise - so do check if you really want/need it.
Ah. Found old bug report that is now closed/fixed.
PS - A note - using /etc/environment means it would be applied everywhere. So it may also affect thunderbird and anything else that might recognize it.
In the future, for things like this, you might consider using a custom .desktop file in ~/.local/share/applications, rather than setting the env var in /etc/environment, to avoid such things.