patch 9.1.0713: Newline causes E749 in Ex mode

Problem:  Newline causes E749 in Ex mode (after 9.1.0573).
Solution: Don't execute empty command followed by a newline.

closes: #15614

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_ex_mode.vim b/src/testdir/test_ex_mode.vim
index aa94935..19d0bec 100644
--- a/src/testdir/test_ex_mode.vim
+++ b/src/testdir/test_ex_mode.vim
Binary files differ