patch 8.2.4609: :unhide does not check for failing to close a window

Problem:    :unhide does not check for failing to close a window.
Solution:   When closing a window fails continue with the next one.  Do not
            try closing the autocmd window. (closes #9984)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4609,
 /**/
     4608,
 /**/