patch 8.1.1577: command line redrawn for +arabic without Arabic characters

Problem:    Command line redrawn for +arabic without Arabic characters.
            (Dominique Pelle)
Solution:   Check if there actually are any Arabic characters.  Do redraw
            after displaying incsearch. (closes #4569)
diff --git a/src/version.c b/src/version.c
index ce9e459..a7dff69 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1577,
+/**/
     1576,
 /**/
     1575,