Don't run term-splitting routine on new installations.

Props pento.
Fixes #30261.
Built from https://develop.svn.wordpress.org/trunk@33621


git-svn-id: http://core.svn.wordpress.org/trunk@33588 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/schema.php

@@ -496,6 +496,9 @@ function populate_options() {
 
 	// 3.5
 	'link_manager_enabled' => 0,
+
+	// 4.3.0
+	'finished_splitting_shared_terms' => 1,
 	);
 
 	// 3.3