Fixed typo causing a warning on some PHP compilations

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@784 a333f486-631f-4898-b8df-5754b55c2be0

application/cmdbabstract.class.inc.php

@@ -1325,7 +1325,7 @@ EOF
 		{
 			$bMandatory = false;
 			$aAllowedValues = MetaModel::GetAllowedValues_att($sClass, $sAttCode, $aArgs);
-			if ($aArgs['default'][$sAttCode])
+			if (isset($aArgs['default'][$sAttCode]))
 			{
 				$oObj->Set($sAttCode, $aArgs['default'][$sAttCode]);			
 			}