patch 8.0.1020: when a timer calls getchar(1) input is overwritten

Problem:    When a timer calls getchar(1) input is overwritten.
Solution:   Increment tb_change_cnt in inchar(). (closes #1940)
diff --git a/src/version.c b/src/version.c
index 980f285..e67ade3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1020,
+/**/
     1019,
 /**/
     1018,