Compiler: take into account the "is_null_allowed" flag for blobs

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@2363 a333f486-631f-4898-b8df-5754b55c2be0

setup/compiler.class.inc.php

@@ -696,6 +696,7 @@ EOF;
 			}
 			elseif ($sAttType == 'AttributeBlob')
 			{
+				$aParameters['is_null_allowed'] = $this->GetPropBoolean($oField, 'is_null_allowed', false);
 				$aParameters['depends_on'] = $sDependencies;
 			}
 			elseif ($sAttType == 'AttributeStopWatch')