patch 8.0.1797: terminal window is redrawn too often

Problem:    Terminal window is redrawn too often and scrolling is repeated.
Solution:   Don't scroll immediately but only when redrawing.  Avoid redrawing
            the whole terminal window on every change.
diff --git a/src/version.c b/src/version.c
index 7fbca85..5fa69e3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1797,
+/**/
     1796,
 /**/
     1795,