Remove VST plugin discovery option from first-start wizard

Because (a) it makes the startup seem "very long and complicated",
and (b) sometimes fails or crashes weirdly,
or (c) a plugin dialog gets hidden behind the main window, or ...

Overall the first impression of the program may be horrible when
the first step includes discovering VST plugins.

gtk2_ardour/new_user_wizard.cc

@@ -60,7 +60,6 @@
 #include "opts.h"
 #include "ui_config.h"
 #include "pbd/i18n.h"
-#include "plugin_scan_dialog.h"
 #include "utils.h"
 
 using namespace std;
@@ -419,20 +418,12 @@ NewUserWizard::setup_final_page ()
 {
 	string msg = string_compose (_("%1 is ready for use"), PROGRAM_NAME);
 
-	plugin_disco_button.signal_clicked().connect (sigc::mem_fun(*this, &NewUserWizard::discover_plugins));
-	plugin_disco_button.set_label (_("Scan for Plugins"));
-	plugin_disco_button.show ();
-
 	Gtk::Label* final_label = manage (new Label);
 	final_label->set_markup (string_compose ("<span weight=\"bold\" size=\"large\">%1</span>", msg));
 	final_label->show ();
 
 	VBox* vbox = manage (new VBox);
 	vbox->pack_start (*final_label, true, true);
-	/* Mixbus sets this parameter to true by default, Ardour sets it to false */
-	if (!Config->get_discover_vst_on_start()) {
-		vbox->pack_start (plugin_disco_button, true, false);
-	}
 	vbox->show ();
 
 	final_page_index = append_page (*vbox);
@@ -441,14 +432,6 @@ NewUserWizard::setup_final_page ()
 	set_page_type (*vbox, ASSISTANT_PAGE_CONFIRM);
 }
 
-void
-NewUserWizard::discover_plugins ()
-{
-	plugin_disco_button.set_sensitive (false);
-	PluginScanDialog psd (false, true);
-	psd.start ();
-}
-
 void
 NewUserWizard::on_cancel ()
 {

gtk2_ardour/new_user_wizard.h

@@ -57,7 +57,6 @@ private:
 	void on_apply ();
 	void on_cancel ();
 	bool on_delete_event (GdkEventAny*);
-	void discover_plugins ();
 
 	Glib::RefPtr<Gdk::Pixbuf> icon_pixbuf;
 
@@ -98,7 +97,6 @@ private:
 	/* final page */
 
 	void setup_final_page ();
-	Gtk::Button plugin_disco_button;
 
 	/* always there */