keikai doesn't update the selected cell upon clicking under mobile browsers

Steps to Reproduce

1. run the zul with chrome device simulator, choose iPad mini
2. select any cell other than A1 e.g. B2
3. click the button to print the selected cell

Current Result

the printed label is A1:A1

Expected Result

the printed label is B2:B2

Debug Information

• only double-click can update the selected cell.