Fix context menu w/o an active object

Also remove special case when no items are selected,
since this only has one or two menu items, one being the add menu
which can be better accessed from the header or add shortcut.

If the no-selection case is to have it's own alternate menu - it should
be more complete before enabling.

release/scripts/startup/bl_ui/space_node.py

@@ -328,12 +328,15 @@ class NODE_MT_specials(Menu):
         layout = self.layout
 
         # If nothing is selected
+        # (disabled for now until it can be made more useful).
+        '''
         selected_nodes_len = len(context.selected_nodes)
         if selected_nodes_len == 0:
             layout.operator_context = 'INVOKE_DEFAULT'
             layout.menu("NODE_MT_add")
             layout.operator("node.clipboard_paste", text="Paste")
             return
+        '''
 
         # If something is selected
         layout.operator_context = 'INVOKE_DEFAULT'