init: do parse _all_ core.* settings early

init: do parse _all_ core.* settings early

In Git for Windows, `has_symlinks` is set to 0 by default. Therefore, we
need to parse the config setting `core.symlinks` to know if it has been
set to `true`. In `git init`, we must do that before copying the
templates because they might contain symbolic links.

Even if the support for symbolic links on Windows has not made it to
upstream Git yet, we really should make sure that all the `core.*`
settings are parsed before proceeding, as they might very well change
the behavior of `git init` in a way the user intended.

This fixes https://github.com/git-for-windows/git/issues/3414

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>