patch 8.2.1221: memory leak when updating popup window

Problem:    Memory leak when updating popup window.
Solution:   Clear search highlighting.
diff --git a/src/version.c b/src/version.c
index 424234b..f0cfe69 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1221,
+/**/
     1220,
 /**/
     1219,