patch 9.1.0709: GUIEnter event not found in Turkish locale

Problem:   GUIEnter not found in Turkish locale
           (James McCoy, after v9.1.0256, the issue was there before,
            but v9.1.0256 made it more apparent)
Solution:  explicitly compare autocommand events by ASCII value and
           ignoring locale, because according to the documentation,
           events are case insensitive (:h autocommand-events)

fixes: #15574
closes: #15603

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/highlight.c b/src/highlight.c
index d3ea2d2..0928952 100644
--- a/src/highlight.c
+++ b/src/highlight.c
@@ -1215,8 +1215,8 @@
 
 	target.key = 0;
 	target.value = (char *)arg;
-	target.length = 0;	// not used, see cmp_keyvalue_value_i()
-	entry = (keyvalue_T *)bsearch(&target, &color_name_tab, ARRAY_LENGTH(color_name_tab), sizeof(color_name_tab[0]), cmp_keyvalue_value_i);
+	target.length = 0;	// not used, see cmp_keyvalue_value_ni()
+	entry = (keyvalue_T *)bsearch(&target, &color_name_tab, ARRAY_LENGTH(color_name_tab), sizeof(color_name_tab[0]), cmp_keyvalue_value_ni);
 	if (entry == NULL)
 	{
 	    semsg(_(e_color_name_or_number_not_recognized_str), key_start);
@@ -2542,8 +2542,8 @@
 
     target.key = 0;
     target.value = (char *)name;
-    target.length = 0;		// not used, see cmp_keyvalue_value_i()
-    entry = (keyvalue_T *)bsearch(&target, &rgb_tab, ARRAY_LENGTH(rgb_tab), sizeof(rgb_tab[0]), cmp_keyvalue_value_i);
+    target.length = 0;		// not used, see cmp_keyvalue_value_ni()
+    entry = (keyvalue_T *)bsearch(&target, &rgb_tab, ARRAY_LENGTH(rgb_tab), sizeof(rgb_tab[0]), cmp_keyvalue_value_ni);
     if (entry != NULL)
 	return gui_adjust_rgb((guicolor_T)entry->key);