Resolve issue blocking partner_firstname from installation

This change fixes this bug: OCA#1677

With that the module can be installed as only partners with names will be processed

partner_firstname/models/res_partner.py

@@ -214,7 +214,7 @@ def _install_partner_firstname(self):
         correctly into the database. This can be called later too if needed.
         """
         # Find records with empty firstname and lastname
-        records = self.search([("firstname", "=", False), ("lastname", "=", False)])
+        records = self.search([("firstname", "=", False), ("lastname", "=", False), ("name", "!=", "")])
 
         # Force calculations there
         records._inverse_name()