patch 8.2.4589: cannot index the g: dictionary

Problem:    Cannot index the g: dictionary.
Solution:   Recognize using "g:[key]". (closes #9969)
diff --git a/src/version.c b/src/version.c
index 6c59f95..6f86d2b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4589,
+/**/
     4588,
 /**/
     4587,