Change how get_settings errors are returned.

git-svn-id: https://develop.svn.wordpress.org/trunk@708 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/functions.php

@@ -550,7 +550,7 @@ function get_settings($setting) {
 		$settings = $cache_settings;
 	}
     if (!isset($settings->$setting)) {
-        error_log("get_settings: Didn't find setting $setting");
+        return false;
     }
     else {
 		return $settings->$setting;