Don't set Torbutton environment variables globally
Originally created by Tails on #5648 (Redmine)
Commit 6a2de87 sets TOR_SOCKS_HOST
and TOR_SOCKS_PORT
globally to
point to the SocksPort dedicated to Iceweasel. If some random piece of
software took these envvars into account, then it would partially defeat
our stream isolation design.
So, we should set these environment variables for Iceweasel only, e.g. in the wrapper that we will probably create anyway for dont autostart iceweasel (#5735 (closed)).
Feature Branch: feature/5648-dont-set-torbutton-environment-globally