rebase: fix white-space

This trailing space was inadvertently introduced in 9fbcc3d203 (Merge
branch 'js/rebase-orig-head-fix', 2019-03-20).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/rebase.c b/builtin/rebase.c
index db6ca9b..2f9041f 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -2109,7 +2109,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	strbuf_addf(&msg, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
 	if (reset_head(&options.onto->object.oid, "checkout", NULL,
-		       RESET_HEAD_DETACH | RESET_ORIG_HEAD | 
+		       RESET_HEAD_DETACH | RESET_ORIG_HEAD |
 		       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
 		       NULL, msg.buf))
 		die(_("Could not detach HEAD"));