bugfix in dca/tl_gallery_albums.php

Fatal error: Uncaught exception Exception with message Query error:
Column 'owner' cannot be null (INSERT INTO tl_gallery_creator_albums
(date, owner, owners_name, uploader, img_resolution, img_quality,
preserve_filename, pid, sorting, tstamp) VALUES (1402321379, NULL, NULL,
'be_gc_jumploader', '600', '1000', 1, 0, 64, 0)) thrown in
system/modules/core/library/Contao/Database/Statement.php on line 283

#0 system/modules/core/library/Contao/Database/Statement.php(254):
Contao\Database\Statement->query()
#1 system/modules/core/drivers/DC_Table.php(677):
Contao\Database\Statement->execute()
#2 system/modules/core/classes/Backend.php(568):
Contao\DC_Table->create()
#3 contao/main.php(142):
Contao\Backend->getBackendModule('gallery_creator')
#4 contao/main.php(293): Main->run()
#5 {