XAPK bugfixes, HTML default User-Agent

lib/pages/app.dart

@@ -444,7 +444,9 @@ class _AppPageState extends State<AppPage> {
               Padding(
                   padding: const EdgeInsets.fromLTRB(0, 8, 0, 0),
                   child: LinearProgressIndicator(
-                      value: app!.downloadProgress! / 100))
+                      value: app!.downloadProgress! >= 0
+                          ? app.downloadProgress! / 100
+                          : null))
           ],
         ));
 

lib/pages/apps.dart

@@ -542,8 +542,12 @@ class AppsPageState extends State<AppsPage> {
                 ? SizedBox(
                     width: 110,
                     child: Text(tr('percentProgress', args: [
-                      listedApps[index].downloadProgress?.toInt().toString() ??
-                          '100'
+                      listedApps[index].downloadProgress! >= 0
+                          ? listedApps[index]
+                              .downloadProgress!
+                              .toInt()
+                              .toString()
+                          : tr('pleaseWait')
                     ])))
                 : trailingRow,
             onTap: () {