(bug 49738) Use correct name for wiki content language

Happens when anonymous user cannot change language, and the
language of the translation differs from the content language.

Change-Id: Ie4f15f1813eec992cfe060baf9cd7dcb5f8a0d95

tests/browser/features/support/pages/panel_page.rb

@@ -2,7 +2,7 @@ class ULSPage
 	include PageObject
 
 	include URL
-	page_url URL.url('?setlang=<%=params[:setlang]%>')
+	page_url URL.url('?<%=params[:extra]%>')
 
 	div(:panel_display, id: 'display-settings-block')
 	div(:panel_input, id: 'input-settings-block')