patch 8.2.1220: memory access error when dragging a popup window

Problem:    memory access error when dragging a popup window over a buffer
            with folding.
Solution:   Avoid going over the end of the cache. (closes #6438)
diff --git a/src/version.c b/src/version.c
index eff7835..424234b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1220,
+/**/
     1219,
 /**/
     1218,