🐛 Fix SynchroAttLinkSet.attribute_qualifier default value

Old typo (in a galaxy far, far away) : 1e688706

synchro/synchrodatasource.class.inc.php

@@ -1658,7 +1658,7 @@ class SynchroAttLinkSet extends SynchroAttribute
 		MetaModel::Init_AddAttribute(new AttributeString('attribute_qualifier', array(
 			'allowed_values' => null,
 			'sql' => 'attribute_qualifier',
-			'default_value' => '\'',
+			'default_value' => '',
 			'is_null_allowed' => true,
 			'depends_on' => array(),
 		)));