fish dies when sourcing /etc/profile

[maxyz]

As mentioned by the fish developers, fish is not a POSIX 1003.1 compatible shell, thus sourcing /etc/profile with it only leads to syntax errors Fish bug #3665

As such, please consider reverting 7a27e1a

This will reopen #879, wich might need a different solution, maybe something like:

$SHELL --login -c "/bin/sh -c '[ -f /etc/profile ] && . /etc/profile; export -p' > $xsess_tmp"

Happy hacking,