Set initial directory title to empty

src/directories.cc

@@ -125,12 +125,14 @@ bool Directories::TreeStore::drag_data_delete_vfunc (const Gtk::TreeModel::Path
 }
 
 Directories::Directories() : Gtk::ListViewText(1) {
-  this->set_enable_tree_lines(true);
+  set_enable_tree_lines(true);
   
   tree_store = TreeStore::create();
   tree_store->set_column_types(column_record);
   set_model(tree_store);
   
+  get_column(0)->set_title("");
+  
   auto renderer=dynamic_cast<Gtk::CellRendererText*>(get_column(0)->get_first_cell());
   get_column(0)->set_cell_data_func(*renderer, [this] (Gtk::CellRenderer *renderer, const Gtk::TreeModel::iterator &iter) {
     if(auto renderer_text=dynamic_cast<Gtk::CellRendererText*>(renderer))