totem_plugin_load_interface() used to call totem_interface_load_with_full_path() which itself called gtk_builder_connect_signals().
And as we didn't do that anymore when we started loading the file ourselves, gtk_widget_hide_on_delete() wasn't called so the dialogue was destroyed which we didn't expect.
With help from Krifa75 firstname.lastname@example.org
Fixes: 2001dfee ("opensubtitles: Fix dialogue not showing up")
Closes: #549 (closed)