[Data Object] Grid: error when activating filters for a select field without a value

[BlackbitDevs]

Expected behavior

No filtering

Actual behavior

Status: 500 | Internal Server Error
URL: /admin/object/grid-proxy/classId/3/folderId/11?xaction=read&_dc=1488440541271
Params:
-> language: en
-> class: inquiry

Fatal error: Uncaught Zend_Db_Statement_Mysqli_Exception: Mysqli prepare error: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')) AND object_3.o_type IN ('object','folder')) ORDER BY o_id ASC LIMIT 25' at line 1 in /home/pimcore_demo/www/vendor/zendframework/zendframework1/library/Zend/Db/Statement/Mysqli.php:77
Stack trace:
#0 /home/pimcore_demo/www/vendor/zendframework/zendframework1/library/Zend/Db/Statement.php(115): Zend_Db_Statement_Mysqli->_prepare('SELECT object_3...')
#1 /home/pimcore_demo/www/vendor/zendframework/zendframework1/library/Zend/Db/Adapter/Mysqli.php(388): Zend_Db_Statement->__construct(Object(Zend_Db_Adapter_Mysqli), 'SELECT object_3...')
#2 /home/pimcore_demo/www/vendor/zendframework/zendframework1/library/Zend/Db/Adapter/Abstract.php(479): Zend_Db_Adapter_Mysqli->prepare('SELECT object_3...')
#3 /home/pimcore_demo/www/vendor/zendframework/zendframework1/library/Zend/Db/Adapter/Abstract.php(794): Zend_Db_Ad in /home/pimcore_demo/www/vendor/zendframework/zendframework1/library/Zend/Db/Statement/Mysqli.php on line 77

Steps to reproduce

1. Create class with select field and add options
2. Create folder
3. create object of the class in 1. in the folder of 2. and set select field to any option
4. save object
5. open folder
6. add the select field column to the table
7. click "Filters" in select field column submenu without actually choosing a value in the Filters submenu