jqxGrid: date filter does not work correctly

[SvetoslavjQWidgets]

Describe the bug When the filter row is enabled and there are columns of type date, the input element does not respond on typing in it

Grid demo: https://www.jqwidgets.com/jquery-widgets-demo/demos/jqxgrid/index.htm#demos/jqxgrid/datefilter.htm

To Reproduce Steps to reproduce the behavior:

1. Go to https://www.jqwidgets.com/jquery-widgets-demo/demos/jqxgrid/datefilter.htm?light
2. Click on a column that is of type date
3. Type in the input field
4. See that nothing is appended to the input element