Description of problem:
Gdbm support isn't included in the dba module, and can't be easily
added as dba is built-in in the current php packages.

Version-Release number of selected component (if applicable):
php-4.3.8-2.1 (previous versions too)

How reproducible:
Always (none of the previous FC2 php packages had gdbm support either).
  
Additional info:
See : http://www.php.net/manual/en/ref.dba.php
Apparently, dbm and ndbm are marked as to be avoided, but not gdbm.
It's still supported, works well, and doesn't add too many more
dependencies (gdbm-devel at build time and gdbm at runtime).
The main concern is that since the dba module is built-in, it can't be
easily replaced. Currently to add gdbm support I must replace the main
php package with one rebuilt without the explicit '--without-gdbm'
configure option.
If a new errata will be made for bug #127518 maybe this could go in
too? It shouldn't be possible for such a minor change to cause
breakage. I'm still curious as to why gdbm was disabled in the first
place, though.