fix(lib): fix `omz_urldecode` unsafe eval bug
fix(lib): fix `omz_urldecode` unsafe eval bug

The `omz_urldecode` function uses an eval to decode the input which can be
exploited to inject commands. This is used only in the svn plugin and it
requires a complex process to exploit, so it is highly unlikely to have been
used by an attacker.

tekniklr/oh-my-zsh,tekniklr/oh-my-zsh