patch 8.2.0459: cannot check if a function name is correct

Problem:    Cannot check if a function name is correct.
Solution:   Add "?funcname" to exists().
diff --git a/src/version.c b/src/version.c
index 46b58c2..9cbdec6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    459,
+/**/
     458,
 /**/
     457,