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)

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1699,
 /**/
     1698,
 /**/