Fix: init specimen

htdocs/societe/class/societe.class.php

@@ -2548,6 +2548,7 @@ class Societe extends CommonObject
         $this->id=0;
         $this->name = 'THIRDPARTY SPECIMEN '.dol_print_date($now,'dayhourlog');
         $this->nom = $this->name;   // For backward compatibility
+        $this->ref_ext = 'Ref ext';
         $this->specimen=1;
         $this->address='21 jump street';
         $this->zip='99999';