[FIX] models: update field transient only, and do not modify state

Fixes regression introduced at 4d9e36a459
that caused all custom (manual) models to be reset to "base" models.

This prevented the creation and proper use of custom models.

opw-657017
Closes #9670

Partial version of #9663

openerp/models.py

@@ -374,10 +374,10 @@ class BaseModel(object):
             context = {}
         cr.execute("""
             UPDATE ir_model
-               SET name=%s, info=%s, state='base', transient=%s
+               SET transient=%s
              WHERE model=%s
          RETURNING id
-        """, [self._description, self.__doc__, self._transient, self._name])
+        """, [self._transient, self._name])
         if not cr.rowcount:
             cr.execute('SELECT nextval(%s)', ('ir_model_id_seq',))
             model_id = cr.fetchone()[0]