patch 8.0.1433: illegal memory access after undo

Problem:    Illegal memory access after undo. (Dominique Pelle)
Solution:   Avoid the column becomes negative. (Christian Brabandt,
            closes #2533)
diff --git a/src/version.c b/src/version.c
index 2a3460e..6ebb01a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1433,
+/**/
     1432,
 /**/
     1431,