Fix code execution bug on zsh.
Fix code execution bug on zsh.

Use $2 instead of $1 in zsh preexec

https://github.com/Neki/fasd/commit/72f707941af354b56d751186fc535766712a900d
http://zsh.sourceforge.net/Doc/Release/Functions.html

Neki/fasd,alphapapa/fasd,allcatsarebeautiful/fasd,clvv/fasd,dankilman/fasd