patch 9.0.0301: the message window popup is delayed after an error message

Problem:    The message window popup is delayed after an error message.
Solution:   Do not set emsg_on_display when using the message window.
diff --git a/src/version.c b/src/version.c
index fcd142e..31e8182 100644
--- a/src/version.c
+++ b/src/version.c
@@ -708,6 +708,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    301,
+/**/
     300,
 /**/
     299,