getLanguageLinks should warn if two interwiki links point to the same site
getLanguageLinks should warn if two interwiki links point to the same site

If "result" dictionary has a site as key then warn if it tries to overwrite
that key value.

Bug: T116995
Change-Id: I88cbdc1928d30ff555d4e816205c91ab3a2b46f8

darthbhyrava/pywikibot-local,jayvdb/pywikibot-core,hasteur/g13bot_tools_new,hasteur/g13bot_tools_new,npdoty/pywikibot,PersianWikipedia/pywikibot-core,magul/pywikibot-core,hasteur/g13bot_tools_new,h4ck3rm1k3/pywikibot-core,jayvdb/pywikibot-core,wikimedia/pywikibot-core,smalyshev/pywikibot-core,happy5214/pywikibot-core,wikimedia/pywikibot-core,Darkdadaah/pywikibot-core,happy5214/pywikibot-core,Darkdadaah/pywikibot-core,npdoty/pywikibot,magul/pywikibot-core,h4ck3rm1k3/pywikibot-core