Better kiwix-serve default loading if no welcome page is defined in ZIM (ID: 3417227)

src/common/kiwix/reader.cpp

@@ -124,6 +124,10 @@ namespace kiwix {
     if (this->zimFileHandler->getFileheader().hasMainPage()) {
       zim::Article article = zimFileHandler->getArticle(this->zimFileHandler->getFileheader().getMainPage());
       url = article.getLongUrl();
+
+      if (url.empty()) {
+	url = getFirstPageUrl(); 
+      }
     }
     
     return url;