[#169582166] Fix bug: 'index' case table column header should always fit
[#169582166] Fix bug: 'index' case table column header should always fit

Before, on some browsers, the 'x' would go to the next line.

concord-consortium/codap,concord-consortium/codap,concord-consortium/codap,concord-consortium/codap,concord-consortium/codap