Description:
------------
In ext/dba/dba_db4.c, the DB_INIT_LOCK bit is set in the gmode flag
passed into dbp->open().  This is not a valid option for opening a
BDB4 DB.  The DBA code may have accidently worked against earlier
versions of BDB because the integer value of the option previously
matched a valid value.

Tested with BDB 4.7.25

For debugging, note in BDB's db-4.7.25/db/db_iface.c the OKFLAGS macro
doesn't include DB_INIT_LOCK.



Reproduce code:
---------------
<?php
$filename = "/tmp/dba1.db";
$d = dba_open($filename, "c", "db4");
?>

Expected result:
----------------
No error

Actual result:
--------------
Warning: dba_open(/tmp/dba1.db,c): Driver initialization failed for handler: db4: Invalid argument in dba1.php on line 5