git: update to v2.7.0

Update to git version v2.7.0.

* Upstream commit ed1c9977cb1b63e4270ad8bdf967a2d02580aa08 (Remove
  get_object_hash.) changed API:

  Convert all instances of get_object_hash to use an appropriate
  reference to the hash member of the oid member of struct object.
  This provides no functional change, as it is essentially a macro
  substitution.

Signed-off-by: Christian Hesse <mail@eworm.de>

ui-clone.c

@@ -24,7 +24,7 @@ static int print_ref_info(const char *refname, const struct object_id *oid,
 	if (obj->type == OBJ_TAG) {
 		if (!(obj = deref_tag(obj, refname, 0)))
 			return 0;
-		htmlf("%s\t%s^{}\n", sha1_to_hex(obj->sha1), refname);
+		htmlf("%s\t%s^{}\n", oid_to_hex(&obj->oid), refname);
 	}
 	return 0;
 }