handlerpageedit: Retain comment when clicking preview

handlers/handlerpageedit.cpp

@@ -114,7 +114,7 @@ Response HandlerPageEdit::handleRequest(PageDao &pageDao, std::string pagename,
 			templatePage.setVar("content", newContent);
 			setPageVars(templatePage, pagename);
 			templatePage.setVar("title", createPageTitle("Preview: " + pagename));
-
+			templatePage.setVar("comment", r.post("comment"));
 			Response response;
 			response.setBody(templatePage.render());
 			return response;