make the login box be centered again on firefox/linux

src/login.php

@@ -200,7 +200,7 @@ echo html_tag( 'table',
                                     '<div style="text-align: center;">'. addSubmit(_("Login")) .'</div>',
                                     'left' )
                                 ),
-                        '', $color[4], 'border="0" width="350"' ) . '</div>',
+                        '', $color[4], 'border="0" width="350" align="center"' ) . '</div>',
                         'center' )
                         ) ,
                         '', $color[4], 'border="0" cellspacing="0" cellpadding="0" width="100%"' );
@@ -209,4 +209,4 @@ echo '</form>' . "\n";
 do_hook('login_bottom');
 
 ?>
-</body></html>
+</body></html>