[zsh] zsh compinit: insecure directories

I got the same warnings when I sudo -i starting a root shell, @chakrit's solution didn't work for me.

But I found -u switch of compinit works, e.g. in your .zshrc/zshenv or where you called compinit

compinit -u

NB: Not recommended for production system

See also http://zsh.sourceforge.net/Doc/Release/Completion-System.html#Initialization