Fix: bad sql request

htdocs/comm/propal/class/propal.class.php

@@ -3088,6 +3088,7 @@ class PropaleLigne  extends CommonObject
         if (empty($this->special_code)) $this->special_code=0;
         if (empty($this->fk_parent_line)) $this->fk_parent_line=0;
         if (empty($this->fk_fournprice)) $this->fk_fournprice=0;
+        if (empty($this->subprice)) $this->subprice=0;
 
 		if (empty($this->pa_ht)) $this->pa_ht=0;