Deprecate llurl= in favour of llprop=url for action=query&prop=langlinks

New props will be added with I54c66c8935b0dbbf3bf8e292236119597f1cbe41

Change-Id: I1340b18b51bccdfaaddec6a16df320d5f6e5acfa
Merge "Deprecate llurl= in favour of llprop=url for action=query&prop=langlinks"