patch 8.0.0857: terminal test fails on MS-Windows

Problem:    Terminal test fails on MS-Windows.
Solution:   Sleep a fraction of a second.
diff --git a/src/version.c b/src/version.c
index b8d0203..1c01f4f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    857,
+/**/
     856,
 /**/
     855,