新增配置项office.preview.switch.disabled，控制offic文件预览切换开关

jodconverter-web/src/main/java/cn/keking/service/impl/PdfFilePreviewImpl.java

@@ -44,6 +44,7 @@ public class PdfFilePreviewImpl implements FilePreview {
         String baseUrl = BaseUrlFilter.getBaseUrl();
         String pdfName = fileName.substring(0, fileName.lastIndexOf(".") + 1) + "pdf";
         String outFilePath = FILE_DIR + pdfName;
+        model.addAttribute("switchDisabled", ConfigConstants.getOfficePreviewSwitchDisabled());
         if (OfficeFilePreviewImpl.OFFICE_PREVIEW_TYPE_IMAGE.equals(officePreviewType) || OfficeFilePreviewImpl.OFFICE_PREVIEW_TYPE_ALL_IMAGES.equals(officePreviewType)) {
             //当文件不存在时，就去下载
             if (!fileUtils.listConvertedFiles().containsKey(pdfName) || !ConfigConstants.isCacheEnabled()) {