patch 8.2.0422: crash when passing popup window to win_splitmove()

Problem:    Crash when passing popup window to win_splitmove(). (john Devin)
Solution:   Disallow moving a popup window. (closes #5816)
diff --git a/src/version.c b/src/version.c
index 986a29f..a6112ce 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    422,
+/**/
     421,
 /**/
     420,