Remove or make verbose some debugging prints

The message about SpatialMaterial conversion was turned into a warning,
as it can potentially interfere with porting projects from Godot 3.x
(if there's a bug in the conversion code).

editor/editor_node.cpp

@@ -4236,7 +4236,6 @@ void EditorNode::_dock_make_float() {
 	Size2 dock_size = dock->get_size() + borders * 2; // remember size
 	Point2 dock_screen_pos = dock->get_global_position() + get_tree()->get_root()->get_position() - borders;
 
-	print_line("dock pos: " + dock->get_global_position() + " window pos: " + get_tree()->get_root()->get_position());
 	int dock_index = dock->get_index();
 	dock_slot[dock_popup_selected]->remove_child(dock);