Fix the header to the top of the table on the Progress page

[bubafinder]

I'm submitting a...

• Bug report
• Regression (a behavior that used to work and stopped working in a new release)
• Feature request
• Documentation issue or request
• Enhancement

Context

Fix the header to the top of the table on the Progress page.

[rkusan00]

Transferred → tailor-cms/author#516