Fix td instead of th in sessions table header (#9162)

Fix #9130

app/views/auth/registrations/_sessions.html.haml

@@ -8,7 +8,7 @@
         %th= t 'sessions.browser'
         %th= t 'sessions.ip'
         %th= t 'sessions.activity'
-        %td
+        %th
     %tbody
       - @sessions.each do |session|
         %tr