package/zsh: enable static regex module

the builtin string =~ regexp operator needs to load the regex
module. This operator is used very often in zsh scripts, so
link it statically to avoid the overhead of dynamic loading.

Signed-off-by: Norbert Lange <nolange79@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>