Small change to fix `case` parse error

[RodrigoDLPontes]

Small change to fix parse error in case statement.

For some reason, I get the following error with the current code:

/home/rdeleulopesp/dotfiles/extra/plugins/zsh/zsh-vi-mode/zsh-vi-mode.zsh:1999: parse error near `)'

My zsh version is:

zsh 5.4.1 (x86_64-unknown-linux-gnu)

Perhaps the syntax with | is not portable to all versions? I believe this change would not affect functionality, and it fixes the error for me.

Let me know if additional information is needed.