[PATCH] Use POSIX sed invocation

[David Bremner]

On Sun,  3 Jul 2011 10:18:17 +0100, Robin Green <greenrd at greenrd.org> wrote:
> Fixes broken build on DragonFly BSD

> -	sed  -n 's/^\s*\(notmuch_[a-z_]*\)\s*(.*/\t\1;/p' $< >> notmuch.sym
> +	sed  -n 's/^[[:space:]]*\(notmuch_[a-z_]*\)[[:space:]]*(.*/'"`printf "\t"`"'\1;/p' $< >> notmuch.sym

Fix (for my naughty GNUism) pushed.

Thanks for your patch

David