Fix template selector notebook behaviour

Also replace "validate" button with standard refresh icon button.

Fixes: lp:1773510
https://bugs.launchpad.net/kicad/+bug/1773510

kicad/dialogs/dialog_template_selector.cpp

@@ -114,6 +114,8 @@ void DIALOG_TEMPLATE_SELECTOR::OnPageChange( wxNotebookEvent& event )
 
     if( page != wxNOT_FOUND && (unsigned)page < m_panels.size() )
         m_tcTemplatePath->SetValue( m_panels[page]->GetPath() );
+
+    event.Skip();
 }