pt import: Fix two warnings from valgrind

- Remove uninitialised unused variable
- Remove jump condition on uninitialised variable

gtk2_ardour/editor_pt_import.cc

@@ -76,8 +76,6 @@ using std::string;
 void
 Editor::external_pt_dialog ()
 {
-	std::string ptpath;
-
 	if (_session == 0) {
 		MessageDialog msg (_("You can't import a PT session until you have a session loaded."));
 		msg.run ();

gtk2_ardour/pt_import_selector.cc

@@ -46,10 +46,6 @@ PTImportSelector::PTImportSelector (PTFFormat& ptf) :
 {
 	_ptf = &ptf;
 
-	if (!_session_rate) {
-		Gtk::Dialog::response(RESPONSE_CANCEL);
-	}
-
 	set_size_request (800, 450);
 	ptimport_import_button.set_size_request (90, 35);
 	ptimport_cancel_button.set_size_request (90, 35);