patch 8.2.4696: delete() with "rf" argument does not report a failure

Problem:    delete() with "rf" argument does not report a failure.
Solution:   Return -1 if the directory could not be removed. (closes #10078)

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4696,
 /**/
     4695,
 /**/