'main': Test for redirection earlier.
'main': Test for redirection earlier.

This is a prerequisite for the next commit.

The incumbent code was wrong: the test of $in_redirection in the first hunk
would never have seen «(( in_redirection == 2 ))».  That had no visible
effect since options to sudo don't look like redirection operators.

psprint/zsh-syntax-highlighting,P71/zsh-syntax-highlighting,x-way/zsh-syntax-highlighting,m0vie/zsh-syntax-highlighting,zsh-users/zsh-syntax-highlighting,danielshahaf/zsh-syntax-highlighting-debian,zsh-users/zsh-syntax-highlighting,psprint/zsh-syntax-highlighting,joshuarubin/dotfiles,P71/zsh-syntax-highlighting,x-way/zsh-syntax-highlighting,phy1729/zsh-syntax-highlighting,joshuarubin/dotfiles,joshuarubin/dotfiles,stuha/wbr-zsh,danielshahaf/zsh-syntax-highlighting,m0vie/zsh-syntax-highlighting,phy1729/zsh-syntax-highlighting,danielshahaf/zsh-syntax-highlighting,joshuarubin/dotfiles,danielshahaf/zsh-syntax-highlighting-debian