MDL-40220 use new core_component::get_plugin_list()

lib/editor/tinymce/all_strings.php

@@ -68,7 +68,7 @@ foreach ($string as $key=>$value) {
 }
 
 // Add subplugin strings, accept only those with proper pluginname prefix with colon.
-foreach (get_plugin_list('tinymce') as $component => $ignored) {
+foreach (core_component::get_plugin_list('tinymce') as $component => $ignored) {
     $componentstrings = get_string_manager()->load_component_strings(
             'tinymce_' . $component, $lang);
     foreach ($componentstrings as $key => $value) {