look in the localdb for dependencies

Obviously the dependencies for AUR packages will not be located in the
sync dbs...

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
remove useless depchain argument

This useless argument is a product of the fact that get_pkg_chain_size
was originally intended to be recursive.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>