* [ui] support for showing message on load data failed in doc app.

module/doc/lang/en.php

@@ -505,6 +505,7 @@ $lang->doc->docLang->createModule                = $lang->doc->addCatalog;
 $lang->doc->docLang->leaveEditingConfirm         = 'The document is currently being edited. Do you want to leave the editing page?';
 $lang->doc->docLang->saveDocFailed               = 'Failed to save the document';
 $lang->doc->docLang->loadingDocsData             = 'Loading document data...';
+$lang->doc->docLang->loadDataFailed              = 'Load data failed.';
 $lang->doc->docLang->noSpaceTip                  = 'No space, please create one.';
 $lang->doc->docLang->searchModulePlaceholder     = 'Search directory';
 $lang->doc->docLang->searchDocPlaceholder        = 'Search document';

module/doc/lang/zh-cn.php

@@ -506,6 +506,7 @@ $lang->doc->docLang->createModule                = $lang->doc->addCatalog;
 $lang->doc->docLang->leaveEditingConfirm         = '文档编辑中，确定要离开吗？';
 $lang->doc->docLang->saveDocFailed               = '文档保存失败，请稍后重试';
 $lang->doc->docLang->loadingDocsData             = '正在加载文档数据...';
+$lang->doc->docLang->loadDataFailed              = '加载数据失败';
 $lang->doc->docLang->noSpaceTip                  = '这里什么也没有，先创建一个空间再使用吧！';
 $lang->doc->docLang->searchModulePlaceholder     = '搜索目录';
 $lang->doc->docLang->searchDocPlaceholder        = '搜索文档';