submodule: skip redundant active entries when pattern covers path

submodule: skip redundant active entries when pattern covers path

configure_added_submodule always writes an explicit
submodule.<name>.active entry, even when the new
path is already matched by submodule.active
patterns. This leads to unnecessary and cluttered configuration.

change the logic to centralize wildmatch-based pattern lookup,
in configure_added_submodule. Wrap the active-entry write in a conditional
that only fires when that helper reports no existing pattern covers the
submodule’s path.

Signed-off-by: K Jayatheerth <jayatheerthkulkarni2005@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>