config.txt: correct the note about uploadpack.packObjectsHook

Document for uploadpack.packObjectsHook is added in [1] and consists
of two paragraphs, the second one is quite important about where this
variable can stay.

When the paragraph about uploadpack.allowFilter is added in [2], it's
added in between the two paragraphs. This makes the "this is non-repo
level config" note incorrectly apply to allowFilter instead of
packObjectsHook. Move allowFilter paragraph down to fix this.

[1] 20b20a22f8 (upload-pack: provide a hook for running pack-objects -
    2016-05-18)

[2] 10ac85c785 (upload-pack: add object filtering for partial clone -
    2017-12-08)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -3268,15 +3268,15 @@ uploadpack.packObjectsHook::
 	was run. I.e., `upload-pack` will feed input intended for
 	`pack-objects` to the hook, and expects a completed packfile on
 	stdout.
-
-uploadpack.allowFilter::
-	If this option is set, `upload-pack` will advertise partial
-	clone and partial fetch object filtering.
 +
 Note that this configuration variable is ignored if it is seen in the
 repository-level config (this is a safety measure against fetching from
 untrusted repositories).
 
+uploadpack.allowFilter::
+	If this option is set, `upload-pack` will support partial
+	clone and partial fetch object filtering.
+
 url.<base>.insteadOf::
 	Any URL that starts with this value will be rewritten to
 	start, instead, with <base>. In cases where some site serves a