Merge pull request #7723 from atm-maxime/fix_contract_desc

Fix : contract lines from origin were containing all lines desc

htdocs/contrat/card.php

@@ -327,7 +327,7 @@
 										$label = $lines[$i]->product_label;
 									}
 
-									$desc .= ($lines[$i]->desc && $lines[$i]->desc!=$lines[$i]->libelle)?dol_htmlentitiesbr($lines[$i]->desc):'';
+									$desc = ($lines[$i]->desc && $lines[$i]->desc!=$lines[$i]->libelle)?dol_htmlentitiesbr($lines[$i]->desc):'';
 								}
 								else {
 								    $desc = dol_htmlentitiesbr($lines[$i]->desc);