Fix can not open new tab for email

(cherry picked from commit f5c569ad340d66d27cf676b4de9602a41ed93fb5)

lib/main/pages/app_pages.dart

@@ -55,6 +55,14 @@ class AppPages {
         mailbox_dashboard.loadLibrary,
         () => mailbox_dashboard.MailboxDashBoardView()),
       binding: MailboxDashBoardBindings()),
+    GetPage(
+      name: AppRoutes.dashboardWithParameter,
+      page: () => DeferredWidget(
+        mailbox_dashboard.loadLibrary,
+        () => mailbox_dashboard.MailboxDashBoardView()
+      ),
+      binding: MailboxDashBoardBindings()
+    ),
     GetPage(
       name: AppRoutes.mailtoURL,
       page: () => DeferredWidget(

lib/main/routes/app_routes.dart

@@ -3,6 +3,7 @@ abstract class AppRoutes {
   static const login = '/login';
   static const session = '/session';
   static const dashboard = '/dashboard';
+  static const dashboardWithParameter = '/dashboard/:id';
   static const settings = '/settings';
   static const composer = '/composer';
   static const destinationPicker = '/destination_picker';