title: Odoo Warning "Perhaps a module was partially removed or renamed"
body: <p>When I run odoo server, I got this warning message below.</p>
  
  <p>WARNING dietfacts2 openerp.modules.loading: Model product.nutrientitem is declared but cannot be loaded! (Perhaps a module was partially removed or renamed)</p>
  
  <p>I know that it shows this warning message because I created the model name but then I changed it afterward. The model was saved to postgres DB. I tried to delete the table in DB but unsuccessful.</p>
  
  <p>dietfacts2=# delete from ir_model where model = 'product.nutrientitem';
  ERROR:  null value in column "model" violates not-null constraint
  DETAIL:  Failing row contains (1011, 2017-02-20 04:15:05.207869, 2017-02-20 04:15:05.207869, 285, null, f, false, product_nutrientitem_write_uid_fkey, null, null, null, null).
  CONTEXT:  SQL statement "UPDATE ONLY "public"."ir_model_constraint" SET "model" = NULL WHERE $1 OPERATOR(pg_catalog.=) "model""</p>