Fix (unreported) sculpt vertex color panel visible for all object types

Since DATA_PT_sculpt_vertex_colors has its own poll() we need to call
the poll() of MeshButtonsPanel as well

Differential Revision: https://developer.blender.org/D8563

release/scripts/startup/bl_ui/properties_data_mesh.py

@@ -468,7 +468,7 @@ class DATA_PT_sculpt_vertex_colors(MeshButtonsPanel, Panel):
 
     @classmethod
     def poll(cls, context):
-        return context.preferences.experimental.use_sculpt_vertex_colors
+        return super().poll(context) and context.preferences.experimental.use_sculpt_vertex_colors
 
     def draw(self, context):
         layout = self.layout