TranslatePage#workflow_state_element needs some time to appear

Fixed failed Jenkins job:

https://wmf.ci.cloudbees.com/view/r-tr/job/Translate-meta.wikimedia.org-
linux-firefox/127/testReport/(root)/Special_Translate/Workflow_selector_
being_clickable/

Change-Id: I1d1333801a30e6902983c0df7fe1c94e97980854