patch 8.2.0447: terminal scroll tests fails on some systems

Problem:    Terminal scroll tests fails on some systems.
Solution:   Remove the fixed 100msec wait for Win32.  Add a loop to wait until
            scrolling has finished. (James McCoy, closes #5842)
diff --git a/src/version.c b/src/version.c
index 6b5e252..b54ac5a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    447,
+/**/
     446,
 /**/
     445,