merge-file: run setup_git_directory_gently() sooner

Part of a campaign to make repository-local configuration
available early (simplifying the startup sequence for
built-in commands).

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git.c b/git.c
index 89bce65..286a359 100644
--- a/git.c
+++ b/git.c
@@ -350,7 +350,7 @@
 		{ "mailsplit", cmd_mailsplit },
 		{ "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 		{ "merge-base", cmd_merge_base, RUN_SETUP },
-		{ "merge-file", cmd_merge_file },
+		{ "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 		{ "merge-index", cmd_merge_index, RUN_SETUP },
 		{ "merge-ours", cmd_merge_ours, RUN_SETUP },
 		{ "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },