Move install wizard invocations to one place

Fixes bugs whereby install wizard invoked from the GUI was missing
various things, such as updating recently used list, setting up
timers, etc.

gui/qt/main_window.py

@@ -50,7 +50,6 @@ from network_dialog import NetworkDialog
 from qrcodewidget import QRCodeWidget, QRDialog
 from qrtextedit import ShowQRTextEdit
 from transaction_dialog import show_transaction
-from installwizard import InstallWizard
 
 
 
@@ -385,10 +384,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         if storage.file_exists:
             self.show_critical(_("File exists"))
             return
-        wizard = InstallWizard(self.app, self.config, self.network, storage)
-        wallet = wizard.run('new')
-        if wallet:
-            self.new_window(full_path)
+        self.gui_object.install_wizard(storage, 'new')
 
     def init_menubar(self):
         menubar = QMenuBar()