urlmatch: enable normalization of URLs with globs

urlmatch: enable normalization of URLs with globs

The `url_normalize` function is used to validate and normalize URLs. As
such, it does not allow for some special characters to be part of the
URLs that are to be normalized. As we want to allow using globs in some
configuration keys making use of URLs, namely `http.<url>.<key>`, but
still normalize them, we need to somehow enable some additional allowed
characters.

To do this without having to change all callers of `url_normalize`,
where most do not actually want globbing at all, we split off another
function `url_normalize_1`. This function accepts an additional
parameter `allow_globs`, which is subsequently called by `url_normalize`
with `allow_globs=0`.

As of now, this function is not used with globbing enabled. A caller
will be added in the following commit.

Signed-off-by: Patrick Steinhardt <patrick.steinhardt@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>