Description:
------------
PHP prints the following message:
?Notice:  Unknown:  \xac\x13\xb7(null) in Unknown on line 0?
if  
  * the script is running via apache2handler
  * and the dba handler is db4
  * and the dba file does not yet exists
  
The problem will not occur if another dba handler is used, or the script is executed via PHP's cli.

Reproduce code:
---------------
<?php
$dba = dba_open('db4.db', 'c', 'db4');
dba_insert('question', 'bug or feature?', $dba);
dba_insert('answer', '42', $dba);
printf("%s\n", dba_fetch('question', $dba));
?>

Expected result:
----------------
bug or feature?


Actual result:
--------------
bug or feature?
Notice:  Unknown:  \xac\x13\xb7(null) in Unknown on line 0