patch 8.1.1699: highlight_ga can be local instead of global

Problem:    Highlight_ga can be local instead of global.
Solution:   Move highlight_ga into highlight.c. (Yegappan Lakshmanan,
            closes #4675)
diff --git a/src/version.c b/src/version.c
index f6fed49..8548005 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1699,
+/**/
     1698,
 /**/
     1697,