submodule sync: Update "submodule.<name>.url"

When "git submodule sync" synchronizes the repository URLs
it only updates submodules' .git/config.  However, the old
URLs still exist in the super-project's .git/config.

Update the super-project's configuration so that commands
such as "git submodule update" use the URLs from .gitmodules.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-submodule.sh

@@ -839,10 +839,11 @@ cmd_sync()
 		if test -e "$path"/.git
 		then
 		(
+			say "Synchronizing submodule url for '$name'"
+			git config submodule."$name".url "$url"
 			clear_local_git_env
 			cd "$path"
 			remote=$(get_default_remote)
-			say "Synchronizing submodule url for '$name'"
 			git config remote."$remote".url "$url"
 		)
 		fi

t/t7403-submodule-sync.sh

@@ -58,6 +58,9 @@ test_expect_success '"git submodule sync" should update submodule URLs' '
 	(cd super-clone/submodule &&
 	 git checkout master &&
 	 git pull
+	) &&
+	(cd super-clone &&
+	 test -d "$(git config submodule.submodule.url)"
 	)
 '