[FIX] sap.ui.table.*: Fixes that SHIFT+TAB w/o column header does not work
[FIX] sap.ui.table.*: Fixes that SHIFT+TAB w/o column header does not work

- when there is no column header displayed, it was not possible to leave the table by SHIFT+TAB. This is now fixed.

Change-Id: I2ad09c0b5b7673c15b3c82e9f7ee33460e24b0ef
BCP: 1580016702

cschuff/openui5,SAP/openui5,cschuff/openui5,nzamani/openui5,SQCLabs/openui5,SQCLabs/openui5,nzamani/openui5,olirogers/openui5,SAP/openui5,SAP/openui5,olirogers/openui5,nzamani/openui5,SAP/openui5,SQCLabs/openui5,cschuff/openui5,olirogers/openui5